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btrfs: remove btrfs_folio_end_all_writers()

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The function btrfs_folio_end_all_writers() is only utilized in
extent_writepage() as a way to unlock all subpage range (for both
successful submission and error handling).

Meanwhile we have a similar function, btrfs_folio_end_writer_lock().

The difference is, btrfs_folio_end_writer_lock() expects a range that is
a subset of the already locked range.

This limit on btrfs_folio_end_writer_lock() is a little overkilled,
preventing it from being utilized for error paths.

So here we enhance btrfs_folio_end_writer_lock() to accept a superset of
the locked range, and only end the locked subset.
This means we can replace btrfs_folio_end_all_writers() with
btrfs_folio_end_writer_lock() instead.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo
2024-08-30 16:48:20 +09:30
committed by David Sterba
parent ca283ea992
commit ab6eac7c91
3 changed files with 10 additions and 51 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
fs/btrfs/extent_io.c
View File

@@ -1466,7 +1466,8 @@ static int extent_writepage(struct folio *folio, struct btrfs_bio_ctrl *bio_ctrl
mapping_set_error(folio->mapping, ret);
}
btrfs_folio_end_all_writers(inode_to_fs_info(inode), folio);
btrfs_folio_end_writer_lock(inode_to_fs_info(inode), folio,
page_start, PAGE_SIZE);
ASSERT(ret <= 0);
return ret;
}

57
fs/btrfs/subpage.c
View File

@@ -322,6 +322,8 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf
const int start_bit = subpage_calc_start_bit(fs_info, folio, locked, start, len);
const int nbits = (len >> fs_info->sectorsize_bits);
unsigned long flags;
unsigned int cleared = 0;
int bit = start_bit;
bool last;
btrfs_subpage_assert(fs_info, folio, start, len);
@@ -339,11 +341,12 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf
return true;
}
ASSERT(atomic_read(&subpage->writers) >= nbits);
/* The target range should have been locked. */
ASSERT(bitmap_test_range_all_set(subpage->bitmaps, start_bit, nbits));
bitmap_clear(subpage->bitmaps, start_bit, nbits);
last = atomic_sub_and_test(nbits, &subpage->writers);
for_each_set_bit_from(bit, subpage->bitmaps, start_bit + nbits) {
clear_bit(bit, subpage->bitmaps);
cleared++;
}
ASSERT(atomic_read(&subpage->writers) >= cleared);
last = atomic_sub_and_test(cleared, &subpage->writers);
spin_unlock_irqrestore(&subpage->lock, flags);
return last;
}
@@ -825,50 +828,6 @@ bool btrfs_subpage_find_writer_locked(const struct btrfs_fs_info *fs_info,
return found;
}
/*
* Unlike btrfs_folio_end_writer_lock() which unlocks a specified subpage range,
* this ends all writer locked ranges of a page.
*
* This is for the locked page of extent_writepage(), as the locked page
* can contain several locked subpage ranges.
*/
void btrfs_folio_end_all_writers(const struct btrfs_fs_info *fs_info, struct folio *folio)
{
struct btrfs_subpage *subpage = folio_get_private(folio);
u64 folio_start = folio_pos(folio);
u64 cur = folio_start;
ASSERT(folio_test_locked(folio));
if (!btrfs_is_subpage(fs_info, folio->mapping)) {
folio_unlock(folio);
return;
}
/* The page has no new delalloc range locked on it. Just plain unlock. */
if (atomic_read(&subpage->writers) == 0) {
folio_unlock(folio);
return;
}
while (cur < folio_start + PAGE_SIZE) {
u64 found_start;
u32 found_len;
bool found;
bool last;
found = btrfs_subpage_find_writer_locked(fs_info, folio, cur,
&found_start, &found_len);
if (!found)
break;
last = btrfs_subpage_end_and_test_writer(fs_info, folio,
found_start, found_len);
if (last) {
folio_unlock(folio);
break;
}
cur = found_start + found_len;
}
}
#define GET_SUBPAGE_BITMAP(subpage, fs_info, name, dst) \
{ \
const int sectors_per_page = fs_info->sectors_per_page; \

1
fs/btrfs/subpage.h
View File

@@ -109,7 +109,6 @@ void btrfs_folio_set_writer_lock(const struct btrfs_fs_info *fs_info,
bool btrfs_subpage_find_writer_locked(const struct btrfs_fs_info *fs_info,
struct folio *folio, u64 search_start,
u64 *found_start_ret, u32 *found_len_ret);
void btrfs_folio_end_all_writers(const struct btrfs_fs_info *fs_info, struct folio *folio);
/*
* Template for subpage related operations.