The patch titled
Subject: filemap: find_get_entries() now updates start offset
has been added to the -mm mm-unstable branch. Its filename is
filemap-find_get_entries-now-updates-start-offset.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/filemap-find_get_entries-now-updates-start-offset.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Vishal Moola (Oracle)" <vishal.moola@xxxxxxxxx>
Subject: filemap: find_get_entries() now updates start offset
Date: Mon, 17 Oct 2022 09:18:00 -0700
Initially, find_get_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_get_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/20221017161800.2003-3-vishal.moola@xxxxxxxxx
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 13 +++++++++++--
mm/internal.h | 2 +-
mm/shmem.c | 11 ++++-------
mm/truncate.c | 19 +++++++------------
4 files changed, 23 insertions(+), 22 deletions(-)
--- a/mm/filemap.c~filemap-find_get_entries-now-updates-start-offset
+++ a/mm/filemap.c
@@ -2048,10 +2048,10 @@ reset:
*
* Return: The number of entries which were found.
*/
-unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
+unsigned find_get_entries(struct address_space *mapping, pgoff_t *start,
pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices)
{
- XA_STATE(xas, &mapping->i_pages, start);
+ XA_STATE(xas, &mapping->i_pages, *start);
struct folio *folio;
rcu_read_lock();
@@ -2062,6 +2062,15 @@ unsigned find_get_entries(struct address
}
rcu_read_unlock();
+ if (folio_batch_count(fbatch)) {
+ unsigned long nr = 1;
+ int idx = folio_batch_count(fbatch) - 1;
+
+ folio = fbatch->folios[idx];
+ if (!xa_is_value(folio) && !folio_test_hugetlb(folio))
+ nr = folio_nr_pages(folio);
+ *start = indices[idx] + nr;
+ }
return folio_batch_count(fbatch);
}
--- a/mm/internal.h~filemap-find_get_entries-now-updates-start-offset
+++ a/mm/internal.h
@@ -108,7 +108,7 @@ static inline void force_page_cache_read
unsigned find_lock_entries(struct address_space *mapping, pgoff_t *start,
pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
-unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
+unsigned find_get_entries(struct address_space *mapping, pgoff_t *start,
pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices);
void filemap_free_folio(struct address_space *mapping, struct folio *folio);
int truncate_inode_folio(struct address_space *mapping, struct folio *folio);
--- a/mm/shmem.c~filemap-find_get_entries-now-updates-start-offset
+++ a/mm/shmem.c
@@ -973,7 +973,7 @@ static void shmem_undo_range(struct inod
while (index < end) {
cond_resched();
- if (!find_get_entries(mapping, index, end - 1, &fbatch,
+ if (!find_get_entries(mapping, &index, end - 1, &fbatch,
indices)) {
/* If all gone or hole-punch or unfalloc, we're done */
if (index == start || end != -1)
@@ -985,13 +985,12 @@ static void shmem_undo_range(struct inod
for (i = 0; i < folio_batch_count(&fbatch); i++) {
folio = fbatch.folios[i];
- index = indices[i];
if (xa_is_value(folio)) {
if (unfalloc)
continue;
- if (shmem_free_swap(mapping, index, folio)) {
+ if (shmem_free_swap(mapping, indices[i], folio)) {
/* Swap was replaced by page: retry */
- index--;
+ index = indices[i];
break;
}
nr_swaps_freed++;
@@ -1004,19 +1003,17 @@ static void shmem_undo_range(struct inod
if (folio_mapping(folio) != mapping) {
/* Page was replaced by swap: retry */
folio_unlock(folio);
- index--;
+ index = indices[i];
break;
}
VM_BUG_ON_FOLIO(folio_test_writeback(folio),
folio);
truncate_inode_folio(mapping, folio);
}
- index = folio->index + folio_nr_pages(folio) - 1;
folio_unlock(folio);
}
folio_batch_remove_exceptionals(&fbatch);
folio_batch_release(&fbatch);
- index++;
}
spin_lock_irq(&info->lock);
--- a/mm/truncate.c~filemap-find_get_entries-now-updates-start-offset
+++ a/mm/truncate.c
@@ -400,7 +400,7 @@ void truncate_inode_pages_range(struct a
index = start;
while (index < end) {
cond_resched();
- if (!find_get_entries(mapping, index, end - 1, &fbatch,
+ if (!find_get_entries(mapping, &index, end - 1, &fbatch,
indices)) {
/* If all gone from start onwards, we're done */
if (index == start)
@@ -414,21 +414,18 @@ void truncate_inode_pages_range(struct a
struct folio *folio = fbatch.folios[i];
/* We rely upon deletion not changing page->index */
- index = indices[i];
if (xa_is_value(folio))
continue;
folio_lock(folio);
- VM_BUG_ON_FOLIO(!folio_contains(folio, index), folio);
+ VM_BUG_ON_FOLIO(!folio_contains(folio, indices[i]), folio);
folio_wait_writeback(folio);
truncate_inode_folio(mapping, folio);
folio_unlock(folio);
- index = folio_index(folio) + folio_nr_pages(folio) - 1;
}
truncate_folio_batch_exceptionals(mapping, &fbatch, indices);
folio_batch_release(&fbatch);
- index++;
}
}
EXPORT_SYMBOL(truncate_inode_pages_range);
@@ -636,16 +633,15 @@ int invalidate_inode_pages2_range(struct
folio_batch_init(&fbatch);
index = start;
- while (find_get_entries(mapping, index, end, &fbatch, indices)) {
+ while (find_get_entries(mapping, &index, end, &fbatch, indices)) {
for (i = 0; i < folio_batch_count(&fbatch); i++) {
struct folio *folio = fbatch.folios[i];
/* We rely upon deletion not changing folio->index */
- index = indices[i];
if (xa_is_value(folio)) {
if (!invalidate_exceptional_entry2(mapping,
- index, folio))
+ indices[i], folio))
ret = -EBUSY;
continue;
}
@@ -655,13 +651,13 @@ int invalidate_inode_pages2_range(struct
* If folio is mapped, before taking its lock,
* zap the rest of the file in one hit.
*/
- unmap_mapping_pages(mapping, index,
- (1 + end - index), false);
+ unmap_mapping_pages(mapping, indices[i],
+ (1 + end - indices[i]), false);
did_range_unmap = 1;
}
folio_lock(folio);
- VM_BUG_ON_FOLIO(!folio_contains(folio, index), folio);
+ VM_BUG_ON_FOLIO(!folio_contains(folio, indices[i]), folio);
if (folio->mapping != mapping) {
folio_unlock(folio);
continue;
@@ -684,7 +680,6 @@ int invalidate_inode_pages2_range(struct
folio_batch_remove_exceptionals(&fbatch);
folio_batch_release(&fbatch);
cond_resched();
- index++;
}
/*
* For DAX we invalidate page tables after invalidating page cache. We
_
Patches currently in -mm which might be from vishal.moola@xxxxxxxxx are
filemap-find_lock_entries-now-updates-start-offset.patch
filemap-find_get_entries-now-updates-start-offset.patch
