mm: shmem: factor out the within_size logic into a new helper

Factor out the within_size logic into a new helper to remove duplicate
code.

Link: https://lkml.kernel.org/r/527dea9d7e32fe6b94c7fe00df2c126203017911.1738918357.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/shmem.c b/mm/shmem.c
index f5a081563022cd06b8a09dbdb0fc52e14c05665a..8de9b4a07a8afe73561cab79ccac5378b9003760 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -590,6 +590,28 @@ shmem_mapping_size_orders(struct address_space *mapping, pgoff_t index, loff_t w
        return order > 0 ? BIT(order + 1) - 1 : 0;
 }
 
+static unsigned int shmem_get_orders_within_size(struct inode *inode,
+               unsigned long within_size_orders, pgoff_t index,
+               loff_t write_end)
+{
+       pgoff_t aligned_index;
+       unsigned long order;
+       loff_t i_size;
+
+       order = highest_order(within_size_orders);
+       while (within_size_orders) {
+               aligned_index = round_up(index + 1, 1 << order);
+               i_size = max(write_end, i_size_read(inode));
+               i_size = round_up(i_size, PAGE_SIZE);
+               if (i_size >> PAGE_SHIFT >= aligned_index)
+                       return within_size_orders;
+
+               order = next_order(&within_size_orders, order);
+       }
+
+       return 0;
+}
+
 static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index,
                                              loff_t write_end, bool shmem_huge_force,
                                              struct vm_area_struct *vma,
@@ -598,9 +620,6 @@ static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index
        unsigned int maybe_pmd_order = HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER ?
                0 : BIT(HPAGE_PMD_ORDER);
        unsigned long within_size_orders;
-       unsigned int order;
-       pgoff_t aligned_index;
-       loff_t i_size;
 
        if (!S_ISREG(inode->i_mode))
                return 0;
@@ -634,16 +653,11 @@ static unsigned int shmem_huge_global_enabled(struct inode *inode, pgoff_t index
                        within_size_orders = shmem_mapping_size_orders(inode->i_mapping,
                                                                       index, write_end);
 
-               order = highest_order(within_size_orders);
-               while (within_size_orders) {
-                       aligned_index = round_up(index + 1, 1 << order);
-                       i_size = max(write_end, i_size_read(inode));
-                       i_size = round_up(i_size, PAGE_SIZE);
-                       if (i_size >> PAGE_SHIFT >= aligned_index)
-                               return within_size_orders;
+               within_size_orders = shmem_get_orders_within_size(inode, within_size_orders,
+                                                                 index, write_end);
+               if (within_size_orders > 0)
+                       return within_size_orders;
 
-                       order = next_order(&within_size_orders, order);
-               }
                fallthrough;
        case SHMEM_HUGE_ADVISE:
                if (vm_flags & VM_HUGEPAGE)
@@ -1747,10 +1761,7 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode,
        unsigned long mask = READ_ONCE(huge_shmem_orders_always);
        unsigned long within_size_orders = READ_ONCE(huge_shmem_orders_within_size);
        unsigned long vm_flags = vma ? vma->vm_flags : 0;
-       pgoff_t aligned_index;
        unsigned int global_orders;
-       loff_t i_size;
-       int order;
 
        if (thp_disabled_by_hw() || (vma && vma_thp_disabled(vma, vm_flags)))
                return 0;
@@ -1776,17 +1787,7 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode,
                return READ_ONCE(huge_shmem_orders_inherit);
 
        /* Allow mTHP that will be fully within i_size. */
-       order = highest_order(within_size_orders);
-       while (within_size_orders) {
-               aligned_index = round_up(index + 1, 1 << order);
-               i_size = round_up(i_size_read(inode), PAGE_SIZE);
-               if (i_size >> PAGE_SHIFT >= aligned_index) {
-                       mask |= within_size_orders;
-                       break;
-               }
-
-               order = next_order(&within_size_orders, order);
-       }
+       mask |= shmem_get_orders_within_size(inode, within_size_orders, index, 0);
 
        if (vm_flags & VM_HUGEPAGE)
                mask |= READ_ONCE(huge_shmem_orders_madvise);