From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: proc: remove m_cache_vma Instead of setting m->version in the show method, set it in m_next(), where it should be. Also remove the fallback code for failing to find a vma, or version being zero. Link: http://lkml.kernel.org/r/20200317193201.9924-2-adobriyan@xxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 38 ++++++-------------------------------- 1 file changed, 6 insertions(+), 32 deletions(-) --- a/fs/proc/task_mmu.c~proc-remove-m_cache_vma +++ a/fs/proc/task_mmu.c @@ -131,21 +131,14 @@ m_next_vma(struct proc_maps_private *pri return vma->vm_next ?: priv->tail_vma; } -static void m_cache_vma(struct seq_file *m, struct vm_area_struct *vma) -{ - if (m->count < m->size) /* vma is copied successfully */ - m->version = m_next_vma(m->private, vma) ? vma->vm_end : -1UL; -} - static void *m_start(struct seq_file *m, loff_t *ppos) { struct proc_maps_private *priv = m->private; unsigned long last_addr = m->version; struct mm_struct *mm; struct vm_area_struct *vma; - unsigned int pos = *ppos; - /* See m_cache_vma(). Zero at the start or after lseek. */ + /* See m_next(). Zero at the start or after lseek. */ if (last_addr == -1UL) return NULL; @@ -170,28 +163,11 @@ static void *m_start(struct seq_file *m, hold_task_mempolicy(priv); priv->tail_vma = get_gate_vma(mm); - if (last_addr) { - vma = find_vma(mm, last_addr - 1); - if (vma && vma->vm_start <= last_addr) - vma = m_next_vma(priv, vma); - if (vma) - return vma; - } - - m->version = 0; - if (pos < mm->map_count) { - for (vma = mm->mmap; pos; pos--) { - m->version = vma->vm_start; - vma = vma->vm_next; - } + vma = find_vma(mm, last_addr); + if (vma) return vma; - } - - /* we do not bother to update m->version in this case */ - if (pos == mm->map_count && priv->tail_vma) - return priv->tail_vma; - return NULL; + return priv->tail_vma; } static void *m_next(struct seq_file *m, void *v, loff_t *pos) @@ -201,6 +177,8 @@ static void *m_next(struct seq_file *m, (*pos)++; next = m_next_vma(priv, v); + m->version = next ? next->vm_start : -1UL; + return next; } @@ -359,7 +337,6 @@ done: static int show_map(struct seq_file *m, void *v) { show_map_vma(m, v); - m_cache_vma(m, v); return 0; } @@ -843,8 +820,6 @@ static int show_smap(struct seq_file *m, seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); show_smap_vma_flags(m, vma); - m_cache_vma(m, vma); - return 0; } @@ -1883,7 +1858,6 @@ static int show_numa_map(struct seq_file seq_printf(m, " kernelpagesize_kB=%lu", vma_kernel_pagesize(vma) >> 10); out: seq_putc(m, '\n'); - m_cache_vma(m, vma); return 0; } _
