This is a note to let you know that I've just added the patch titled
btrfs: fix a compilation error if DEBUG is defined in btree_dirty_folio
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-fix-a-compilation-error-if-debug-is-defined-in-btree_dirty_folio.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5e0e879926c1ce7e1f5e0dfaacaf2d105f7d8a05 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@xxxxxxxx>
Date: Tue, 22 Aug 2023 13:50:51 +0800
Subject: btrfs: fix a compilation error if DEBUG is defined in btree_dirty_folio
From: Qu Wenruo <wqu@xxxxxxxx>
commit 5e0e879926c1ce7e1f5e0dfaacaf2d105f7d8a05 upstream.
[BUG]
After commit 72a69cd03082 ("btrfs: subpage: pack all subpage bitmaps
into a larger bitmap"), the DEBUG section of btree_dirty_folio() would
no longer compile.
[CAUSE]
If DEBUG is defined, we would do extra checks for btree_dirty_folio(),
mostly to make sure the range we marked dirty has an extent buffer and
that extent buffer is dirty.
For subpage, we need to iterate through all the extent buffers covered
by that page range, and make sure they all matches the criteria.
However commit 72a69cd03082 ("btrfs: subpage: pack all subpage bitmaps
into a larger bitmap") changes how we store the bitmap, we pack all the
16 bits bitmaps into a larger bitmap, which would save some space.
This means we no longer have btrfs_subpage::dirty_bitmap, instead the
dirty bitmap is starting at btrfs_subpage_info::dirty_offset, and has a
length of btrfs_subpage_info::bitmap_nr_bits.
[FIX]
Although I'm not sure if it still makes sense to maintain such code, at
least let it compile.
This patch would let us test the bits one by one through the bitmaps.
CC: stable@xxxxxxxxxxxxxxx # 6.1+
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/disk-io.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -859,6 +859,7 @@ static bool btree_dirty_folio(struct add
struct folio *folio)
{
struct btrfs_fs_info *fs_info = btrfs_sb(mapping->host->i_sb);
+ struct btrfs_subpage_info *spi = fs_info->subpage_info;
struct btrfs_subpage *subpage;
struct extent_buffer *eb;
int cur_bit = 0;
@@ -872,18 +873,19 @@ static bool btree_dirty_folio(struct add
btrfs_assert_tree_write_locked(eb);
return filemap_dirty_folio(mapping, folio);
}
+
+ ASSERT(spi);
subpage = folio_get_private(folio);
- ASSERT(subpage->dirty_bitmap);
- while (cur_bit < BTRFS_SUBPAGE_BITMAP_SIZE) {
+ for (cur_bit = spi->dirty_offset;
+ cur_bit < spi->dirty_offset + spi->bitmap_nr_bits;
+ cur_bit++) {
unsigned long flags;
u64 cur;
- u16 tmp = (1 << cur_bit);
spin_lock_irqsave(&subpage->lock, flags);
- if (!(tmp & subpage->dirty_bitmap)) {
+ if (!test_bit(cur_bit, subpage->bitmaps)) {
spin_unlock_irqrestore(&subpage->lock, flags);
- cur_bit++;
continue;
}
spin_unlock_irqrestore(&subpage->lock, flags);
@@ -896,7 +898,7 @@ static bool btree_dirty_folio(struct add
btrfs_assert_tree_write_locked(eb);
free_extent_buffer(eb);
- cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits);
+ cur_bit += (fs_info->nodesize >> fs_info->sectorsize_bits) - 1;
}
return filemap_dirty_folio(mapping, folio);
}
Patches currently in stable-queue which might be from wqu@xxxxxxxx are
queue-6.1/btrfs-output-extra-debug-info-if-we-failed-to-find-a.patch
queue-6.1/btrfs-fix-a-compilation-error-if-debug-is-defined-in-btree_dirty_folio.patch
