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authorVishal Moola (Oracle) <vishal.moola@gmail.com>2022-10-17 19:17:59 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-11-09 04:37:12 +0300
commit3392ca121872dd8c33015c7703d4981c78819be3 (patch)
tree6d7b09f70f2271aae7c83311c8442e189fa5fff3 /mm/shmem.c
parentd8e454eb44473b2270e2675fb44a9d79dee36097 (diff)
downloadlinux-3392ca121872dd8c33015c7703d4981c78819be3.tar.xz
filemap: find_lock_entries() now updates start offset
Patch series "Rework find_get_entries() and find_lock_entries()", v3. Originally the callers of find_get_entries() and find_lock_entries() were keeping track of the start index themselves as they traverse the search range. This resulted in hacky code such as in shmem_undo_range(): index = folio->index + folio_nr_pages(folio) - 1; where the - 1 is only present to stay in the right spot after incrementing index later. This sort of calculation was also being done on every folio despite not even using index later within that function. These patches change find_get_entries() and find_lock_entries() to calculate the new index instead of leaving it to the callers so we can avoid all these complications. This patch (of 2): Initially, find_lock_entries() was being passed in the start offset as a value. That left the calculation of the offset to the callers. This led to complexity in the callers trying to keep track of the index. Now find_lock_entries() takes in a pointer to the start offset and updates the value to be directly after the last entry found. If no entry is found, the offset is not changed. This gets rid of multiple hacky calculations that kept track of the start offset. Link: https://lkml.kernel.org/r/20221017161800.2003-1-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20221017161800.2003-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c8
1 files changed, 2 insertions, 6 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index c1d8b8a1aa3b..6b560c3915af 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -922,21 +922,18 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
folio_batch_init(&fbatch);
index = start;
- while (index < end && find_lock_entries(mapping, index, end - 1,
+ while (index < end && find_lock_entries(mapping, &index, end - 1,
&fbatch, indices)) {
for (i = 0; i < folio_batch_count(&fbatch); i++) {
folio = fbatch.folios[i];
- index = indices[i];
-
if (xa_is_value(folio)) {
if (unfalloc)
continue;
nr_swaps_freed += !shmem_free_swap(mapping,
- index, folio);
+ indices[i], folio);
continue;
}
- index += folio_nr_pages(folio) - 1;
if (!unfalloc || !folio_test_uptodate(folio))
truncate_inode_folio(mapping, folio);
@@ -945,7 +942,6 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
folio_batch_remove_exceptionals(&fbatch);
folio_batch_release(&fbatch);
cond_resched();
- index++;
}
same_folio = (lstart >> PAGE_SHIFT) == (lend >> PAGE_SHIFT);