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* lockdep: Rename trace_softirqs_{on,off}()Peter Zijlstra2020-03-213-10/+10
| | | | | | | | | | | | | | | | | | | | | Continue what commit: d820ac4c2fa8 ("locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]") started, rename these to avoid confusing them with tracepoints. git grep -l "trace_softirqs_\(on\|off\)" | while read file; do sed -ie 's/trace_softirqs_\(on\|off\)/lockdep_softirqs_\1/g' $file; done Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20200320115859.119434738@infradead.org
* lockdep: Rename trace_hardirq_{enter,exit}()Thomas Gleixner2020-03-214-13/+14
| | | | | | | | | | | | | | Continue what commit: d820ac4c2fa8 ("locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]") started, rename these to avoid confusing them with tracepoints. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20200320115859.060481361@infradead.org
* x86/entry: Rename ___preempt_schedulePeter Zijlstra2020-03-213-12/+12
| | | | | | | | | | | | | | | | | Because moar '_' isn't always moar readable. git grep -l "___preempt_schedule\(_notrace\)*" | while read file; do sed -ie 's/___preempt_schedule\(_notrace\)*/preempt_schedule\1_thunk/g' $file; done Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20200320115858.995685950@infradead.org
* x86: Remove unneeded includesBrian Gerst2020-03-217-12/+0
| | | | | | | | | Clean up includes of and in <asm/syscalls.h> Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-19-brgerst@gmail.com
* x86/entry: Drop asmlinkage from syscallsBrian Gerst2020-03-215-22/+19
| | | | | | | | | | | | | asmlinkage is no longer required since the syscall ABI is now fully under x86 architecture control. This makes the 32-bit native syscalls a bit more effecient by passing in regs via EAX instead of on the stack. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-18-brgerst@gmail.com
* x86/entry/32: Enable pt_regs based syscallsBrian Gerst2020-03-216-114/+64
| | | | | | | | | | | | Enable pt_regs based syscalls for 32-bit. This makes the 32-bit native kernel consistent with the 64-bit kernel, and improves the syscall interface by not needing to push all 6 potential arguments onto the stack. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://lkml.kernel.org/r/20200313195144.164260-17-brgerst@gmail.com
* x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit argumentsBrian Gerst2020-03-215-75/+79
| | | | | | | | | | | | | | | For the 32-bit syscall interface, 64-bit arguments (loff_t) are passed via a pair of 32-bit registers. These register pairs end up in consecutive stack slots, which matches the C ABI for 64-bit arguments. But when accessing the registers directly from pt_regs, the wrapper needs to manually reassemble the 64-bit value. These wrappers already exist for 32-bit compat, so make them available to 32-bit native in preparation for enabling pt_regs-based syscalls. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://lkml.kernel.org/r/20200313195144.164260-16-brgerst@gmail.com
* x86/entry/32: Rename 32-bit specific syscallsBrian Gerst2020-03-212-30/+30
| | | | | | | | | | | | Rename the syscalls that only exist for 32-bit from x86_* to ia32_* to make it clear they are for 32-bit only. Also rename the functions to match the syscall name. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://lkml.kernel.org/r/20200313195144.164260-15-brgerst@gmail.com
* x86/entry/32: Clean up syscall_32.tblBrian Gerst2020-03-211-289/+289
| | | | | | | | | | | | | | | | | | | | | | | After removal of the __ia32_ prefix, remove compat entries that are now identical to the native entry. Converted with this script and fixing up whitespace: while read nr abi name entry compat; do if [ "${nr:0:1}" = "#" ]; then echo $nr $abi $name $entry $compat continue fi if [ "$entry" = "$compat" ]; then compat="" fi echo "$nr $abi $name $entry $compat" done Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-14-brgerst@gmail.com
* x86/entry: Remove ABI prefixes from functions in syscall tablesBrian Gerst2020-03-216-799/+791
| | | | | | | | | | Move the ABI prefixes to the __SYSCALL_[abi]() macros. This allows removal of the need to strip the prefix for UML. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-13-brgerst@gmail.com
* x86/entry/64: Add __SYSCALL_COMMON()Brian Gerst2020-03-214-20/+9
| | | | | | | | | Add a __SYSCALL_COMMON() macro to the syscall table, which simplifies syscalltbl.sh. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-12-brgerst@gmail.com
* x86/entry: Remove syscall qualifier supportBrian Gerst2020-03-216-22/+14
| | | | | | | | | | Syscall qualifier support is no longer needed. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://lkml.kernel.org/r/20200313195144.164260-11-brgerst@gmail.com
* x86/entry/64: Remove ptregs qualifier from syscall tableBrian Gerst2020-03-211-10/+10
| | | | | | | | | | Now that the fast syscall path is removed, the ptregs qualifier is unused. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://lkml.kernel.org/r/20200313195144.164260-10-brgerst@gmail.com
* x86/entry: Move max syscall number calculation to syscallhdr.shBrian Gerst2020-03-2112-72/+24
| | | | | | | | | | Instead of using an array in asm-offsets to calculate the max syscall number, calculate it when writing out the syscall headers. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-9-brgerst@gmail.com
* x86/entry/64: Split X32 syscall table into its own fileBrian Gerst2020-03-213-25/+29
| | | | | | | | | | Since X32 has its own syscall table now, move it to a separate file. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://lkml.kernel.org/r/20200313195144.164260-8-brgerst@gmail.com
* x86/entry/64: Move sys_ni_syscall stub to common.cBrian Gerst2020-03-213-7/+10
| | | | | | | | | | so it can be available to multiple syscall tables. Also directly return -ENOSYS instead of bouncing to the generic sys_ni_syscall(). Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-7-brgerst@gmail.com
* x86/entry/64: Use syscall wrappers for x32_rt_sigreturnBrian Gerst2020-03-213-7/+2
| | | | | | | | | | | Add missing syscall wrapper for x32_rt_sigreturn(). Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-6-brgerst@gmail.com
* x86/entry: Refactor SYS_NI macrosBrian Gerst2020-03-211-9/+23
| | | | | | | | | | | | | Pull the common code out from the SYS_NI macros into a new __SYS_NI macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-5-brgerst@gmail.com
* x86/entry: Refactor COND_SYSCALL macrosBrian Gerst2020-03-211-18/+26
| | | | | | | | | | | | | Pull the common code out from the COND_SYSCALL macros into a new __COND_SYSCALL macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-4-brgerst@gmail.com
* x86/entry: Refactor SYSCALL_DEFINE0 macrosBrian Gerst2020-03-211-41/+32
| | | | | | | | | | | | | Pull the common code out from the SYSCALL_DEFINE0 macros into a new __SYS_STUB0 macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-3-brgerst@gmail.com
* x86/entry: Refactor SYSCALL_DEFINEx macrosBrian Gerst2020-03-211-25/+24
| | | | | | | | | | | | | Pull the common code out from the SYSCALL_DEFINEx macros into a new __SYS_STUBx macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-2-brgerst@gmail.com
* x86/entry/64: Trace irqflags unconditionally as ON when returning to user spaceThomas Gleixner2020-03-102-3/+3
| | | | | | | | | User space cannot disable interrupts any longer so trace return to user space unconditionally as IRQS_ON. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200308222609.314596327@linutronix.de
* x86/entry/32: Remove unused label restore_nocheckThomas Gleixner2020-03-101-1/+1
| | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200308222609.219366430@linutronix.de
* x86/entry/32: Remove the 0/-1 distinction from exception entriesThomas Gleixner2020-02-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | Nothing cares about the -1 "mark as interrupt" in the errorcode of exception entries. It's only used to fill the error code when a signal is delivered, but this is already inconsistent vs. 64 bit as there all exceptions which do not have an error code set it to 0. So if 32 bit applications would care about this, then they would have noticed more than a decade ago. Just use 0 for all excpetions which do not have an errorcode consistently. This does neither break /proc/$PID/syscall because this interface examines the error code / syscall number which is on the stack and that is set to -1 (no syscall) in common_exception unconditionally for all exceptions. The push in the entry stub is just there to fill the hardware error code slot on the stack for consistency of the stack layout. A transient observation of 0 is possible, but that's true for the other exceptions which use 0 already as well and that interface is an unreliable snapshot of dubious correctness anyway. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/87mu94m7ky.fsf@nanos.tec.linutronix.de
* x86/traps: Stop using ist_enter/exit() in do_int3()Andy Lutomirski2020-02-271-6/+15
| | | | | | | | | | | | | | #BP is not longer using IST and using ist_enter() and ist_exit() makes it harder to change ist_enter() and ist_exit()'s behavior. Instead open-code the very small amount of required logic. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200225220217.150607679@linutronix.de
* x86/entry/entry_32: Route int3 through common_exceptionThomas Gleixner2020-02-271-8/+2
| | | | | | | | | | | | | | | int3 is not using the common_exception path for purely historical reasons, but there is no reason to keep it the only exception which is different. Make it use common_exception so the upcoming changes to autogenerate the entry stubs do not have to special case int3. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200225220217.042369808@linutronix.de
* x86/irq: Remove useless return value from do_IRQ()Thomas Gleixner2020-02-272-3/+2
| | | | | | | | | | Nothing is using it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200225220216.826870369@linutronix.de
* x86/traps: Remove redundant declaration of do_double_fault()Thomas Gleixner2020-02-271-7/+7
| | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200225220216.720335354@linutronix.de
* x86/traps: Document do_spurious_interrupt_bug()Thomas Gleixner2020-02-271-0/+19
| | | | | | | | | | | | | | Add a comment which explains why this empty handler for a reserved vector exists. Requested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200225220216.624165786@linutronix.de
* x86/traps: Remove pointless irq enable from do_spurious_interrupt_bug()Thomas Gleixner2020-02-271-1/+0
| | | | | | | | | | | | | | | | That function returns immediately after conditionally reenabling interrupts which is more than pointless and requires the ASM code to disable interrupts again. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20191023123117.871608831@linutronix.de Link: https://lkml.kernel.org/r/20200225220216.518575042@linutronix.de
* x86/entry/32: Force MCE through do_mce()Thomas Gleixner2020-02-273-4/+4
| | | | | | | | | | | | Remove the pointless difference between 32 and 64 bit to make further unifications simpler. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200225220216.428188397@linutronix.de
* x86/mce: Disable tracing and kprobes on do_machine_check()Andy Lutomirski2020-02-272-5/+10
| | | | | | | | | | | | | do_machine_check() can be raised in almost any context including the most fragile ones. Prevent kprobes and tracing. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200225220216.315548935@linutronix.de
* x86/entry/32: Add missing ASM_CLAC to general_protection entryThomas Gleixner2020-02-271-0/+1
| | | | | | | | | | | | | | All exception entry points must have ASM_CLAC right at the beginning. The general_protection entry is missing one. Fixes: e59d1b0a2419 ("x86-32, smap: Add STAC/CLAC instructions to 32-bit kernel entry") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200225220216.219537887@linutronix.de
* Linux 5.6-rc3v5.6-rc3Linus Torvalds2020-02-231-1/+1
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* Merge tag 'for-5.6-rc2-tag' of ↵Linus Torvalds2020-02-237-10/+44
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "These are fixes that were found during testing with help of error injection, plus some other stable material. There's a fixup to patch added to rc1 causing locking in wrong context warnings, tests found one more deadlock scenario. The patches are tagged for stable, two of them now in the queue but we'd like all three released at the same time. I'm not happy about fixes to fixes in such a fast succession during rcs, but I hope we found all the fallouts of commit 28553fa992cb ('Btrfs: fix race between shrinking truncate and fiemap')" * tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents btrfs: fix bytes_may_use underflow in prealloc error condtition btrfs: handle logged extent failure properly btrfs: do not check delayed items are empty for single transaction cleanup btrfs: reset fs_root to NULL on error in open_ctree btrfs: destroy qgroup extent records on transaction abort
| * Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eofFilipe Manana2020-02-211-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While logging the prealloc extents of an inode during a fast fsync we call btrfs_truncate_inode_items(), through btrfs_log_prealloc_extents(), while holding a read lock on a leaf of the inode's root (not the log root, the fs/subvol root), and then that function locks the file range in the inode's iotree. This can lead to a deadlock when: * the fsync is ranged * the file has prealloc extents beyond eof * writeback for a range different from the fsync range starts during the fsync * the size of the file is not sector size aligned Because when finishing an ordered extent we lock first a file range and then try to COW the fs/subvol tree to insert an extent item. The following diagram shows how the deadlock can happen. CPU 1 CPU 2 btrfs_sync_file() --> for range [0, 1MiB) --> inode has a size of 1MiB and has 1 prealloc extent beyond the i_size, starting at offset 4MiB flushes all delalloc for the range [0MiB, 1MiB) and waits for the respective ordered extents to complete --> before task at CPU 1 locks the inode, a write into file range [1MiB, 2MiB + 1KiB) is made --> i_size is updated to 2MiB + 1KiB --> writeback is started for that range, [1MiB, 2MiB + 4KiB) --> end offset rounded up to be sector size aligned btrfs_log_dentry_safe() btrfs_log_inode_parent() btrfs_log_inode() btrfs_log_changed_extents() btrfs_log_prealloc_extents() --> does a search on the inode's root --> holds a read lock on leaf X btrfs_finish_ordered_io() --> locks range [1MiB, 2MiB + 4KiB) --> end offset rounded up to be sector size aligned --> tries to cow leaf X, through insert_reserved_file_extent() --> already locked by the task at CPU 1 btrfs_truncate_inode_items() --> gets an i_size of 2MiB + 1KiB, which is not sector size aligned --> tries to lock file range [2MiB, (u64)-1) --> the start range is rounded down from 2MiB + 1K to 2MiB to be sector size aligned --> but the subrange [2MiB, 2MiB + 4KiB) is already locked by task at CPU 2 which is waiting to get a write lock on leaf X for which we are holding a read lock *** deadlock *** This results in a stack trace like the following, triggered by test case generic/561 from fstests: [ 2779.973608] INFO: task kworker/u8:6:247 blocked for more than 120 seconds. [ 2779.979536] Not tainted 5.6.0-rc2-btrfs-next-53 #1 [ 2779.984503] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2779.990136] kworker/u8:6 D 0 247 2 0x80004000 [ 2779.990457] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] [ 2779.990466] Call Trace: [ 2779.990491] ? __schedule+0x384/0xa30 [ 2779.990521] schedule+0x33/0xe0 [ 2779.990616] btrfs_tree_read_lock+0x19e/0x2e0 [btrfs] [ 2779.990632] ? remove_wait_queue+0x60/0x60 [ 2779.990730] btrfs_read_lock_root_node+0x2f/0x40 [btrfs] [ 2779.990782] btrfs_search_slot+0x510/0x1000 [btrfs] [ 2779.990869] btrfs_lookup_file_extent+0x4a/0x70 [btrfs] [ 2779.990944] __btrfs_drop_extents+0x161/0x1060 [btrfs] [ 2779.990987] ? mark_held_locks+0x6d/0xc0 [ 2779.990994] ? __slab_alloc.isra.49+0x99/0x100 [ 2779.991060] ? insert_reserved_file_extent.constprop.19+0x64/0x300 [btrfs] [ 2779.991145] insert_reserved_file_extent.constprop.19+0x97/0x300 [btrfs] [ 2779.991222] ? start_transaction+0xdd/0x5c0 [btrfs] [ 2779.991291] btrfs_finish_ordered_io+0x4f4/0x840 [btrfs] [ 2779.991405] btrfs_work_helper+0xaa/0x720 [btrfs] [ 2779.991432] process_one_work+0x26d/0x6a0 [ 2779.991460] worker_thread+0x4f/0x3e0 [ 2779.991481] ? process_one_work+0x6a0/0x6a0 [ 2779.991489] kthread+0x103/0x140 [ 2779.991499] ? kthread_create_worker_on_cpu+0x70/0x70 [ 2779.991515] ret_from_fork+0x3a/0x50 (...) [ 2780.026211] INFO: task fsstress:17375 blocked for more than 120 seconds. [ 2780.027480] Not tainted 5.6.0-rc2-btrfs-next-53 #1 [ 2780.028482] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2780.030035] fsstress D 0 17375 17373 0x00004000 [ 2780.030038] Call Trace: [ 2780.030044] ? __schedule+0x384/0xa30 [ 2780.030052] schedule+0x33/0xe0 [ 2780.030075] lock_extent_bits+0x20c/0x320 [btrfs] [ 2780.030094] ? btrfs_truncate_inode_items+0xf4/0x1150 [btrfs] [ 2780.030098] ? rcu_read_lock_sched_held+0x59/0xa0 [ 2780.030102] ? remove_wait_queue+0x60/0x60 [ 2780.030122] btrfs_truncate_inode_items+0x133/0x1150 [btrfs] [ 2780.030151] ? btrfs_set_path_blocking+0xb2/0x160 [btrfs] [ 2780.030165] ? btrfs_search_slot+0x379/0x1000 [btrfs] [ 2780.030195] btrfs_log_changed_extents.isra.8+0x841/0x93e [btrfs] [ 2780.030202] ? do_raw_spin_unlock+0x49/0xc0 [ 2780.030215] ? btrfs_get_num_csums+0x10/0x10 [btrfs] [ 2780.030239] btrfs_log_inode+0xf83/0x1124 [btrfs] [ 2780.030251] ? __mutex_unlock_slowpath+0x45/0x2a0 [ 2780.030275] btrfs_log_inode_parent+0x2a0/0xe40 [btrfs] [ 2780.030282] ? dget_parent+0xa1/0x370 [ 2780.030309] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [ 2780.030329] btrfs_sync_file+0x3f3/0x490 [btrfs] [ 2780.030339] do_fsync+0x38/0x60 [ 2780.030343] __x64_sys_fdatasync+0x13/0x20 [ 2780.030345] do_syscall_64+0x5c/0x280 [ 2780.030348] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 2780.030356] RIP: 0033:0x7f2d80f6d5f0 [ 2780.030361] Code: Bad RIP value. [ 2780.030362] RSP: 002b:00007ffdba3c8548 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 2780.030364] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2d80f6d5f0 [ 2780.030365] RDX: 00007ffdba3c84b0 RSI: 00007ffdba3c84b0 RDI: 0000000000000003 [ 2780.030367] RBP: 000000000000004a R08: 0000000000000001 R09: 00007ffdba3c855c [ 2780.030368] R10: 0000000000000078 R11: 0000000000000246 R12: 00000000000001f4 [ 2780.030369] R13: 0000000051eb851f R14: 00007ffdba3c85f0 R15: 0000557a49220d90 So fix this by making btrfs_truncate_inode_items() not lock the range in the inode's iotree when the target root is a log root, since it's not needed to lock the range for log roots as the protection from the inode's lock and log_mutex are all that's needed. Fixes: 28553fa992cb28 ("Btrfs: fix race between shrinking truncate and fiemap") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extentsFilipe Manana2020-02-191-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In btrfs_wait_ordered_range() once we find an ordered extent that has finished with an error we exit the loop and don't wait for any other ordered extents that might be still in progress. All the users of btrfs_wait_ordered_range() expect that there are no more ordered extents in progress after that function returns. So past fixes such like the ones from the two following commits: ff612ba7849964 ("btrfs: fix panic during relocation after ENOSPC before writeback happens") 28aeeac1dd3080 ("Btrfs: fix panic when starting bg cache writeout after IO error") don't work when there are multiple ordered extents in the range. Fix that by making btrfs_wait_ordered_range() wait for all ordered extents even after it finds one that had an error. Link: https://github.com/kdave/btrfs-progs/issues/228#issuecomment-569777554 CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * btrfs: fix bytes_may_use underflow in prealloc error condtitionJosef Bacik2020-02-191-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I hit the following warning while running my error injection stress testing: WARNING: CPU: 3 PID: 1453 at fs/btrfs/space-info.h:108 btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs] RIP: 0010:btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs] Call Trace: btrfs_free_reserved_data_space+0x4f/0x70 [btrfs] __btrfs_prealloc_file_range+0x378/0x470 [btrfs] elfcorehdr_read+0x40/0x40 ? elfcorehdr_read+0x40/0x40 ? btrfs_commit_transaction+0xca/0xa50 [btrfs] ? dput+0xb4/0x2a0 ? btrfs_log_dentry_safe+0x55/0x70 [btrfs] ? btrfs_sync_file+0x30e/0x420 [btrfs] ? do_fsync+0x38/0x70 ? __x64_sys_fdatasync+0x13/0x20 ? do_syscall_64+0x5b/0x1b0 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 This happens if we fail to insert our reserved file extent. At this point we've already converted our reservation from ->bytes_may_use to ->bytes_reserved. However once we break we will attempt to free everything from [cur_offset, end] from ->bytes_may_use, but our extent reservation will overlap part of this. Fix this problem by adding ins.offset (our extent allocation size) to cur_offset so we remove the actual remaining part from ->bytes_may_use. I validated this fix using my inject-error.py script python inject-error.py -o should_fail_bio -t cache_save_setup -t \ __btrfs_prealloc_file_range \ -t insert_reserved_file_extent.constprop.0 \ -r "-5" ./run-fsstress.sh where run-fsstress.sh simply mounts and runs fsstress on a disk. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * btrfs: handle logged extent failure properlyJosef Bacik2020-02-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we're allocating a logged extent we attempt to insert an extent record for the file extent directly. We increase space_info->bytes_reserved, because the extent entry addition will call btrfs_update_block_group(), which will convert the ->bytes_reserved to ->bytes_used. However if we fail at any point while inserting the extent entry we will bail and leave space on ->bytes_reserved, which will trigger a WARN_ON() on umount. Fix this by pinning the space if we fail to insert, which is what happens in every other failure case that involves adding the extent entry. CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * btrfs: do not check delayed items are empty for single transaction cleanupJosef Bacik2020-02-191-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | btrfs_assert_delayed_root_empty() will check if the delayed root is completely empty, but this is a filesystem-wide check. On cleanup we may have allowed other transactions to begin, for whatever reason, and thus the delayed root is not empty. So remove this check from cleanup_one_transation(). This however can stay in btrfs_cleanup_transaction(), because it checks only after all of the transactions have been properly cleaned up, and thus is valid. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * btrfs: reset fs_root to NULL on error in open_ctreeJosef Bacik2020-02-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running my error injection script I hit a panic when we tried to clean up the fs_root when freeing the fs_root. This is because fs_info->fs_root == PTR_ERR(-EIO), which isn't great. Fix this by setting fs_info->fs_root = NULL; if we fail to read the root. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * btrfs: destroy qgroup extent records on transaction abortJeff Mahoney2020-02-194-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We clean up the delayed references when we abort a transaction but we leave the pending qgroup extent records behind, leaking memory. This patch destroys the extent records when we destroy the delayed refs and makes sure ensure they're gone before releasing the transaction. Fixes: 3368d001ba5d ("btrfs: qgroup: Record possible quota-related extent for qgroup.") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ Rebased to latest upstream, remove to_qgroup() helper, use rbtree_postorder_for_each_entry_safe() wrapper ] Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds2020-02-2310-108/+256
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "More miscellaneous ext4 bug fixes (all stable fodder)" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix mount failure with quota configured as module jbd2: fix ocfs2 corrupt when clearing block group bits ext4: fix race between writepages and enabling EXT4_EXTENTS_FL ext4: rename s_journal_flag_rwsem to s_writepages_rwsem ext4: fix potential race between s_flex_groups online resizing and access ext4: fix potential race between s_group_info online resizing and access ext4: fix potential race between online resizing and write operations ext4: add cond_resched() to __ext4_find_entry() ext4: fix a data race in EXT4_I(inode)->i_disksize
| * | ext4: fix mount failure with quota configured as moduleJan Kara2020-02-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_QFMT_V2 is configured as a module, the test in ext4_feature_set_ok() fails and so mount of filesystems with quota or project features fails. Fix the test to use IS_ENABLED macro which works properly even for modules. Link: https://lore.kernel.org/r/20200221100835.9332-1-jack@suse.cz Fixes: d65d87a07476 ("ext4: improve explanation of a mount failure caused by a misconfigured kernel") Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
| * | jbd2: fix ocfs2 corrupt when clearing block group bitswangyan2020-02-211-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I found a NULL pointer dereference in ocfs2_block_group_clear_bits(). The running environment: kernel version: 4.19 A cluster with two nodes, 5 luns mounted on two nodes, and do some file operations like dd/fallocate/truncate/rm on every lun with storage network disconnection. The fallocate operation on dm-23-45 caused an null pointer dereference. The information of NULL pointer dereference as follows: [577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45. [577992.878290] Aborting journal on device dm-23-45. ... [577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46. [577992.890908] __journal_remove_journal_head: freeing b_committed_data [577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30 [577992.890918] __journal_remove_journal_head: freeing b_committed_data [577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30 [577992.890922] __journal_remove_journal_head: freeing b_committed_data [577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30 [577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30 [577992.890928] __journal_remove_journal_head: freeing b_committed_data [577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30 [577992.890933] __journal_remove_journal_head: freeing b_committed_data [577992.890939] __journal_remove_journal_head: freeing b_committed_data [577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 [577992.890950] Mem abort info: [577992.890951] ESR = 0x96000004 [577992.890952] Exception class = DABT (current EL), IL = 32 bits [577992.890952] SET = 0, FnV = 0 [577992.890953] EA = 0, S1PTW = 0 [577992.890954] Data abort info: [577992.890955] ISV = 0, ISS = 0x00000004 [577992.890956] CM = 0, WnR = 0 [577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9 [577992.890960] [0000000000000020] pgd=0000000000000000 [577992.890964] Internal error: Oops: 96000004 [#1] SMP [577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd) [577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G W OE 4.19.36 #1 [577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019 [577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO) [577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2] [577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2] [577992.891084] sp : ffff0000c8e2b810 [577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000 [577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70 [577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2 [577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30 [577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000 [577992.891097] x19: ffff000001681638 x18: ffffffffffffffff [577992.891098] x17: 0000000000000000 x16: ffff000080a03df0 [577992.891100] x15: ffff0000811d9708 x14: 203d207375746174 [577992.891101] x13: 73203a524f525245 x12: 20373439343a6565 [577992.891103] x11: 0000000000000038 x10: 0101010101010101 [577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f [577992.891109] x7 : 0000000000000000 x6 : 0000000000000080 [577992.891110] x5 : 0000000000000000 x4 : 0000000000000002 [577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00 [577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000 [577992.891116] Call trace: [577992.891139] _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2] [577992.891162] _ocfs2_free_clusters+0x100/0x290 [ocfs2] [577992.891185] ocfs2_free_clusters+0x50/0x68 [ocfs2] [577992.891206] ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2] [577992.891227] ocfs2_add_inode_data+0x94/0xc8 [ocfs2] [577992.891248] ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2] [577992.891269] ocfs2_allocate_extents+0x14c/0x338 [ocfs2] [577992.891290] __ocfs2_change_file_space+0x3f8/0x610 [ocfs2] [577992.891309] ocfs2_fallocate+0xe4/0x128 [ocfs2] [577992.891316] vfs_fallocate+0x11c/0x250 [577992.891317] ksys_fallocate+0x54/0x88 [577992.891319] __arm64_sys_fallocate+0x28/0x38 [577992.891323] el0_svc_common+0x78/0x130 [577992.891325] el0_svc_handler+0x38/0x78 [577992.891327] el0_svc+0x8/0xc My analysis process as follows: ocfs2_fallocate __ocfs2_change_file_space ocfs2_allocate_extents ocfs2_extend_allocation ocfs2_add_inode_data ocfs2_add_clusters_in_btree ocfs2_insert_extent ocfs2_do_insert_extent ocfs2_rotate_tree_right ocfs2_extend_rotate_transaction ocfs2_extend_trans jbd2_journal_restart jbd2__journal_restart /* handle->h_transaction is NULL, * is_handle_aborted(handle) is true */ handle->h_transaction = NULL; start_this_handle return -EROFS; ocfs2_free_clusters _ocfs2_free_clusters _ocfs2_free_suballoc_bits ocfs2_block_group_clear_bits ocfs2_journal_access_gd __ocfs2_journal_access jbd2_journal_get_undo_access /* I think jbd2_write_access_granted() will * return true, because do_get_write_access() * will return -EROFS. */ if (jbd2_write_access_granted(...)) return 0; do_get_write_access /* handle->h_transaction is NULL, it will * return -EROFS here, so do_get_write_access() * was not called. */ if (is_handle_aborted(handle)) return -EROFS; /* bh2jh(group_bh) is NULL, caused NULL pointer dereference */ undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data; If handle->h_transaction == NULL, then jbd2_write_access_granted() does not really guarantee that journal_head will stay around, not even speaking of its b_committed_data. The bh2jh(group_bh) can be removed after ocfs2_journal_access_gd() and before call "bh2jh(group_bh)->b_committed_data". So, we should move is_handle_aborted() check from do_get_write_access() into jbd2_journal_get_undo_access() and jbd2_journal_get_write_access() before the call to jbd2_write_access_granted(). Link: https://lore.kernel.org/r/f72a623f-b3f1-381a-d91d-d22a1c83a336@huawei.com Signed-off-by: Yan Wang <wangyan122@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org
| * | ext4: fix race between writepages and enabling EXT4_EXTENTS_FLEric Biggers2020-02-212-9/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If EXT4_EXTENTS_FL is set on an inode while ext4_writepages() is running on it, the following warning in ext4_add_complete_io() can be hit: WARNING: CPU: 1 PID: 0 at fs/ext4/page-io.c:234 ext4_put_io_end_defer+0xf0/0x120 Here's a minimal reproducer (not 100% reliable) (root isn't required): while true; do sync done & while true; do rm -f file touch file chattr -e file echo X >> file chattr +e file done The problem is that in ext4_writepages(), ext4_should_dioread_nolock() (which only returns true on extent-based files) is checked once to set the number of reserved journal credits, and also again later to select the flags for ext4_map_blocks() and copy the reserved journal handle to ext4_io_end::handle. But if EXT4_EXTENTS_FL is being concurrently set, the first check can see dioread_nolock disabled while the later one can see it enabled, causing the reserved handle to unexpectedly be NULL. Since changing EXT4_EXTENTS_FL is uncommon, and there may be other races related to doing so as well, fix this by synchronizing changing EXT4_EXTENTS_FL with ext4_writepages() via the existing s_writepages_rwsem (previously called s_journal_flag_rwsem). This was originally reported by syzbot without a reproducer at https://syzkaller.appspot.com/bug?extid=2202a584a00fffd19fbf, but now that dioread_nolock is the default I also started seeing this when running syzkaller locally. Link: https://lore.kernel.org/r/20200219183047.47417-3-ebiggers@kernel.org Reported-by: syzbot+2202a584a00fffd19fbf@syzkaller.appspotmail.com Fixes: 6b523df4fb5a ("ext4: use transaction reservation for extent conversion in ext4_end_io") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org
| * | ext4: rename s_journal_flag_rwsem to s_writepages_rwsemEric Biggers2020-02-213-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for making s_journal_flag_rwsem synchronize ext4_writepages() with changes to both the EXTENTS and JOURNAL_DATA flags (rather than just JOURNAL_DATA as it does currently), rename it to s_writepages_rwsem. Link: https://lore.kernel.org/r/20200219183047.47417-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org
| * | ext4: fix potential race between s_flex_groups online resizing and accessSuraj Jitindar Singh2020-02-215-37/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During an online resize an array of s_flex_groups structures gets replaced so it can get enlarged. If there is a concurrent access to the array and this memory has been reused then this can lead to an invalid memory access. The s_flex_group array has been converted into an array of pointers rather than an array of structures. This is to ensure that the information contained in the structures cannot get out of sync during a resize due to an accessor updating the value in the old structure after it has been copied but before the array pointer is updated. Since the structures them- selves are no longer copied but only the pointers to them this case is mitigated. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443 Link: https://lore.kernel.org/r/20200221053458.730016-4-tytso@mit.edu Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
| * | ext4: fix potential race between s_group_info online resizing and accessSuraj Jitindar Singh2020-02-212-21/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During an online resize an array of pointers to s_group_info gets replaced so it can get enlarged. If there is a concurrent access to the array in ext4_get_group_info() and this memory has been reused then this can lead to an invalid memory access. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443 Link: https://lore.kernel.org/r/20200221053458.730016-3-tytso@mit.edu Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Balbir Singh <sblbir@amazon.com> Cc: stable@kernel.org
| * | ext4: fix potential race between online resizing and write operationsTheodore Ts'o2020-02-214-25/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During an online resize an array of pointers to buffer heads gets replaced so it can get enlarged. If there is a racing block allocation or deallocation which uses the old array, and the old array has gotten reused this can lead to a GPF or some other random kernel memory getting modified. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443 Link: https://lore.kernel.org/r/20200221053458.730016-2-tytso@mit.edu Reported-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
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