Subject: + mm-mmap_region-kill-correct_wcount-inode-use-allow_write_access.patch added to -mm tree To: oleg@xxxxxxxxxx,ccross@xxxxxxxxxxx,hughd@xxxxxxxxxx,kosaki.motohiro@xxxxxxxxxxxxxx,rientjes@xxxxxxxxxx,viro@xxxxxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 16 Jul 2013 14:43:31 -0700 The patch titled Subject: mm: mmap_region: kill correct_wcount/inode, use allow_write_access() has been added to the -mm tree. Its filename is mm-mmap_region-kill-correct_wcount-inode-use-allow_write_access.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-mmap_region-kill-correct_wcount-inode-use-allow_write_access.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-mmap_region-kill-correct_wcount-inode-use-allow_write_access.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Oleg Nesterov <oleg@xxxxxxxxxx> Subject: mm: mmap_region: kill correct_wcount/inode, use allow_write_access() correct_wcount and inode in mmap_region() just complicate the code. This boolean was needed previously, when deny_write_access() was called before vma_merge(), now we can simply check VM_DENYWRITE and do allow_write_access() if it is set. allow_write_access() checks file != NULL, so this is safe even if it was possible to use VM_DENYWRITE && !file. Just we need to ensure we use the same file which was deny_write_access()'ed, so the patch also moves "file = vma->vm_file" down after allow_write_access(). Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Colin Cross <ccross@xxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mmap.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff -puN mm/mmap.c~mm-mmap_region-kill-correct_wcount-inode-use-allow_write_access mm/mmap.c --- a/mm/mmap.c~mm-mmap_region-kill-correct_wcount-inode-use-allow_write_access +++ a/mm/mmap.c @@ -1478,11 +1478,9 @@ unsigned long mmap_region(struct file *f { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; - int correct_wcount = 0; int error; struct rb_node **rb_link, *rb_parent; unsigned long charged = 0; - struct inode *inode = file ? file_inode(file) : NULL; /* Check against address space limit. */ if (!may_expand_vm(mm, len >> PAGE_SHIFT)) { @@ -1551,7 +1549,6 @@ munmap_back: error = deny_write_access(file); if (error) goto free_vma; - correct_wcount = 1; } vma->vm_file = get_file(file); error = file->f_op->mmap(file, vma); @@ -1592,11 +1589,10 @@ munmap_back: } vma_link(mm, vma, prev, rb_link, rb_parent); - file = vma->vm_file; - /* Once vma denies write, undo our temporary denial count */ - if (correct_wcount) - atomic_inc(&inode->i_writecount); + if (vm_flags & VM_DENYWRITE) + allow_write_access(file); + file = vma->vm_file; out: perf_event_mmap(vma); @@ -1615,8 +1611,8 @@ out: return addr; unmap_and_free_vma: - if (correct_wcount) - atomic_inc(&inode->i_writecount); + if (vm_flags & VM_DENYWRITE) + allow_write_access(file); vma->vm_file = NULL; fput(file); _ Patches currently in -mm which might be from oleg@xxxxxxxxxx are mm-mempolicy-fix-mbind_range-vma_adjust-interaction.patch include-linux-schedh-dont-use-task-pid-tgid-in-same_thread_group-has_group_leader_pid.patch lockdep-introduce-lock_acquire_exclusive-shared-helper-macros.patch lglock-update-lockdep-annotations-to-report-recursive-local-locks.patch mm-mempolicy-turn-vma_set_policy-into-vma_dup_policy.patch mm-shift-vm_grows-check-from-mmap_region-to-do_mmap_pgoff.patch mm-do_mmap_pgoff-cleanup-the-usage-of-file_inode.patch mm-mmap_region-kill-correct_wcount-inode-use-allow_write_access.patch kernel-wide-fix-missing-validations-on-__get-__put-__copy_to-__copy_from_user.patch autofs4-allow-autofs-to-work-outside-the-initial-pid-namespace.patch autofs4-translate-pids-to-the-right-namespace-for-the-daemon.patch signals-eventpoll-set-saved_sigmask-at-the-start.patch move-exit_task_namespaces-outside-of-exit_notify-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html