/* * linux/mm/msync.c * * Copyright (C) 1994-1999 Linus Torvalds */ /* * The msync() system call. */ #include #include #include #include #include #include /* * MS_SYNC syncs the entire file - including mappings. * * MS_ASYNC does not start I/O (it used to, up to 2.5.67). * Nor does it marks the relevant pages dirty (it used to up to 2.6.17). * Now it doesn't do anything, since dirty pages are properly tracked. * * The application may now run fsync() to * write out the dirty pages and wait on the writeout and check the result. * Or the application may run fadvise(FADV_DONTNEED) against the fd to start * async writeout immediately. * So by _not_ starting I/O in MS_ASYNC we provide complete flexibility to * applications. */ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags) { unsigned long end; struct mm_struct *mm = current->mm; struct vm_area_struct *vma; int unmapped_error = 0; int error = -EINVAL; if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC)) goto out; if (offset_in_page(start)) goto out; if ((flags & MS_ASYNC) && (flags & MS_SYNC)) goto out; error = -ENOMEM; len = (len + ~PAGE_MASK) & PAGE_MASK; end = start + len; if (end < start) goto out; error = 0; if (end == start) goto out; /* * If the interval [start,end) covers some unmapped address ranges, * just ignore them, but return -ENOMEM at the end. */ down_read(&mm->mmap_sem); vma = find_vma(mm, start); for (;;) { struct file *file; loff_t fstart, fend; /* Still start < end. */ error = -ENOMEM; if (!vma) goto out_unlock; /* Here start < vma->vm_end. */ if (start < vma->vm_start) { start = vma->vm_start; if (start >= end) goto out_unlock; unmapped_error = -ENOMEM; } /* Here vma->vm_start <= start < vma->vm_end. */ if ((flags & MS_INVALIDATE) && (vma->vm_flags & VM_LOCKED)) { error = -EBUSY; goto out_unlock; } file = vma->vm_file; fstart = (start - vma->vm_start) + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); fend = fstart + (min(end, vma->vm_end) - start) - 1; start = vma->vm_end; if ((flags & MS_SYNC) && file && (vma->vm_flags & VM_SHARED)) { get_file(file); up_read(&mm->mmap_sem); error = vfs_fsync_range(file, fstart, fend, 1); fput(file); if (error || start >= end) goto out; down_read(&mm->mmap_sem); vma = find_vma(mm, start); } else { if (start >= end) { error = 0; goto out_unlock; } vma = vma->vm_next; } } out_unlock: up_read(&mm->mmap_sem); out: return error ? : unmapped_error; } rm>
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-30 13:18:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-30 13:18:12 -0800
commit751321b3dd5040dc5be19bd23f985e80c914621a (patch)
tree967928e24b38dc7fed918f932bb1b243af42bf7f /net/wireless/Makefile
parent566cf877a1fcb6d6dc0126b076aad062054c2637 (diff)
parent586655d278ba08af7b198b93217746f9a506ee8a (diff)
Merge tag 'rtc-4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC fix from Alexandre Belloni: "A single fix for this cycle. It is worth taking it for 4.10 so that distributions will not have CONFIG_RTC_DRV_JZ4740 switching from m to y in their config. Summary: - Allow jz4740 to build as a module again by using kernel_halt()" * tag 'rtc-4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: rtc: jz4740: make the driver buildable as a module again
Diffstat (limited to 'net/wireless/Makefile')