From 53bee98d004fcd7062f2fe056720704e947e6000 Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Mon, 24 Jul 2023 14:31:48 -0400 Subject: mm: remove re-walk from mmap_region() Using vma_iter_set() will reset the tree and cause a re-walk. Use vmi_iter_config() to set the write to a sub-set of the range. Change the file case to also use vmi_iter_config() so that the end is correctly set. Link: https://lkml.kernel.org/r/20230724183157.3939892-7-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Cc: Peng Zhang Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- mm/mmap.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'mm/mmap.c') diff --git a/mm/mmap.c b/mm/mmap.c index 5fbc7d71d60c..a1a59487390e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2676,8 +2676,11 @@ unsigned long mmap_region(struct file *file, unsigned long addr, next = vma_next(&vmi); prev = vma_prev(&vmi); - if (vm_flags & VM_SPECIAL) + if (vm_flags & VM_SPECIAL) { + if (prev) + vma_iter_next_range(&vmi); goto cannot_expand; + } /* Attempt to expand an old mapping */ /* Check next */ @@ -2698,6 +2701,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, merge_start = prev->vm_start; vma = prev; vm_pgoff = prev->vm_pgoff; + } else if (prev) { + vma_iter_next_range(&vmi); } @@ -2708,9 +2713,9 @@ unsigned long mmap_region(struct file *file, unsigned long addr, goto expanded; } + if (vma == prev) + vma_iter_set(&vmi, addr); cannot_expand: - if (prev) - vma_iter_next_range(&vmi); /* * Determine the object being mapped and call the appropriate @@ -2723,7 +2728,7 @@ cannot_expand: goto unacct_error; } - vma_iter_set(&vmi, addr); + vma_iter_config(&vmi, addr, end); vma->vm_start = addr; vma->vm_end = end; vm_flags_init(vma, vm_flags); @@ -2750,7 +2755,7 @@ cannot_expand: if (WARN_ON((addr != vma->vm_start))) goto close_and_free_vma; - vma_iter_set(&vmi, addr); + vma_iter_config(&vmi, addr, end); /* * If vm_flags changed after call_mmap(), we should try merge * vma again as we may succeed this time. -- cgit