X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fmsync.c;h=4083209b7f02e068b94ac50c16d0739a539bc47b;hb=d327cf7449e6fd5cbac784c641770e9366faa386;hp=090f426bca7d538d5f84c9a8c53a677f50a31434;hpb=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/msync.c b/mm/msync.c index 090f426..4083209 100644 --- a/mm/msync.c +++ b/mm/msync.c @@ -7,181 +7,35 @@ /* * The msync() system call. */ -#include -#include +#include #include #include -#include +#include #include - -#include -#include - -/* - * Called with mm->page_table_lock held to protect against other - * threads/the swapper from ripping pte's out from under us. - */ - -static void sync_pte_range(struct vm_area_struct *vma, pmd_t *pmd, - unsigned long addr, unsigned long end) -{ - pte_t *pte; - - pte = pte_offset_map(pmd, addr); - do { - unsigned long pfn; - struct page *page; - - if (!pte_present(*pte)) - continue; - pfn = pte_pfn(*pte); - if (!pfn_valid(pfn)) - continue; - page = pfn_to_page(pfn); - if (PageReserved(page)) - continue; - - if (ptep_clear_flush_dirty(vma, addr, pte) || - page_test_and_clear_dirty(page)) - set_page_dirty(page); - } while (pte++, addr += PAGE_SIZE, addr != end); - pte_unmap(pte - 1); -} - -static inline void sync_pmd_range(struct vm_area_struct *vma, pud_t *pud, - unsigned long addr, unsigned long end) -{ - pmd_t *pmd; - unsigned long next; - - pmd = pmd_offset(pud, addr); - do { - next = pmd_addr_end(addr, end); - if (pmd_none_or_clear_bad(pmd)) - continue; - sync_pte_range(vma, pmd, addr, next); - } while (pmd++, addr = next, addr != end); -} - -static inline void sync_pud_range(struct vm_area_struct *vma, pgd_t *pgd, - unsigned long addr, unsigned long end) -{ - pud_t *pud; - unsigned long next; - - pud = pud_offset(pgd, addr); - do { - next = pud_addr_end(addr, end); - if (pud_none_or_clear_bad(pud)) - continue; - sync_pmd_range(vma, pud, addr, next); - } while (pud++, addr = next, addr != end); -} - -static void sync_page_range(struct vm_area_struct *vma, - unsigned long addr, unsigned long end) -{ - struct mm_struct *mm = vma->vm_mm; - pgd_t *pgd; - unsigned long next; - - /* For hugepages we can't go walking the page table normally, - * but that's ok, hugetlbfs is memory based, so we don't need - * to do anything more on an msync() */ - if (is_vm_hugetlb_page(vma)) - return; - - BUG_ON(addr >= end); - pgd = pgd_offset(mm, addr); - flush_cache_range(vma, addr, end); - spin_lock(&mm->page_table_lock); - do { - next = pgd_addr_end(addr, end); - if (pgd_none_or_clear_bad(pgd)) - continue; - sync_pud_range(vma, pgd, addr, next); - } while (pgd++, addr = next, addr != end); - spin_unlock(&mm->page_table_lock); -} - -#ifdef CONFIG_PREEMPT -static inline void filemap_sync(struct vm_area_struct *vma, - unsigned long addr, unsigned long end) -{ - const size_t chunk = 64 * 1024; /* bytes */ - unsigned long next; - - do { - next = addr + chunk; - if (next > end || next < addr) - next = end; - sync_page_range(vma, addr, next); - cond_resched(); - } while (addr = next, addr != end); -} -#else -static inline void filemap_sync(struct vm_area_struct *vma, - unsigned long addr, unsigned long end) -{ - sync_page_range(vma, addr, end); -} -#endif +#include /* * MS_SYNC syncs the entire file - including mappings. * - * MS_ASYNC does not start I/O (it used to, up to 2.5.67). Instead, it just - * marks the relevant pages dirty. The application may now run fsync() to + * 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 my _not_ starting I/O in MS_ASYNC we provide complete flexibility to + * So by _not_ starting I/O in MS_ASYNC we provide complete flexibility to * applications. */ -static int msync_interval(struct vm_area_struct *vma, - unsigned long addr, unsigned long end, int flags) -{ - int ret = 0; - struct file *file = vma->vm_file; - - if ((flags & MS_INVALIDATE) && (vma->vm_flags & VM_LOCKED)) - return -EBUSY; - - if (file && (vma->vm_flags & VM_SHARED)) { - filemap_sync(vma, addr, end); - - if (flags & MS_SYNC) { - struct address_space *mapping = file->f_mapping; - int err; - - ret = filemap_fdatawrite(mapping); - if (file->f_op && file->f_op->fsync) { - /* - * We don't take i_sem here because mmap_sem - * is already held. - */ - err = file->f_op->fsync(file,file->f_dentry,1); - if (err && !ret) - ret = err; - } - err = filemap_fdatawait(mapping); - if (!ret) - ret = err; - } - } - return ret; -} - -asmlinkage long sys_msync(unsigned long start, size_t len, int flags) +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, error = -EINVAL; - - if (flags & MS_SYNC) - current->flags |= PF_SYNCWRITE; + int unmapped_error = 0; + int error = -EINVAL; - down_read(¤t->mm->mmap_sem); if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC)) goto out; if (start & ~PAGE_MASK) @@ -200,37 +54,50 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags) * If the interval [start,end) covers some unmapped address ranges, * just ignore them, but return -ENOMEM at the end. */ - vma = find_vma(current->mm, start); - unmapped_error = 0; + down_read(&mm->mmap_sem); + vma = find_vma(mm, start); for (;;) { + struct file *file; + /* Still start < end. */ error = -ENOMEM; if (!vma) - goto out; + goto out_unlock; /* Here start < vma->vm_end. */ if (start < vma->vm_start) { - unmapped_error = -ENOMEM; start = vma->vm_start; + if (start >= end) + goto out_unlock; + unmapped_error = -ENOMEM; } /* Here vma->vm_start <= start < vma->vm_end. */ - if (end <= vma->vm_end) { - if (start < end) { - error = msync_interval(vma, start, end, flags); - if (error) - goto out; - } - error = unmapped_error; - goto out; + if ((flags & MS_INVALIDATE) && + (vma->vm_flags & VM_LOCKED)) { + error = -EBUSY; + goto out_unlock; } - /* Here vma->vm_start <= start < vma->vm_end < end. */ - error = msync_interval(vma, start, vma->vm_end, flags); - if (error) - goto out; + file = vma->vm_file; start = vma->vm_end; - vma = vma->vm_next; + if ((flags & MS_SYNC) && file && + (vma->vm_flags & VM_SHARED)) { + get_file(file); + up_read(&mm->mmap_sem); + error = vfs_fsync(file, file->f_path.dentry, 0); + 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: - up_read(¤t->mm->mmap_sem); - current->flags &= ~PF_SYNCWRITE; - return error; + return error ? : unmapped_error; }