[PATCH 6.8 560/715] f2fs: compress: fix to cover normal cluster write with cp_rwsem

Sasha Levin
2024-03-24T22:44:12Z

From: Chao Yu <chao@kernel.org>

[ Upstream commit fd244524c2cf07b5f4c3fe8abd6a99225c76544b ]

When we overwrite compressed cluster w/ normal cluster, we should
not unlock cp_rwsem during f2fs_write_raw_pages(), otherwise data
will be corrupted if partial blocks were persisted before CP & SPOR,
due to cluster metadata wasn't updated atomically.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/compress.c | 27 ++++++++++++++++++---------
fs/f2fs/data.c | 3 ++-
2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 3a8d8a213b406..ff26b49c0d71f 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1443,12 +1443,14 @@ void f2fs_compress_write_end_io(struct bio *bio, struct page *page)
}

static int f2fs_write_raw_pages(struct compress_ctx *cc,
- int *submitted,
+ int *submitted_p,
struct writeback_control *wbc,
enum iostat_type io_type)
{
struct address_space *mapping = cc->inode->i_mapping;
- int _submitted, compr_blocks, ret, i;
+ struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
+ int submitted, compr_blocks, i;
+ int ret = 0;

compr_blocks = f2fs_compressed_blocks(cc);

@@ -1463,6 +1465,10 @@ static int f2fs_write_raw_pages(struct compress_ctx *cc,
if (compr_blocks < 0)
return compr_blocks;

+ /* overwrite compressed cluster w/ normal cluster */
+ if (compr_blocks > 0)
+ f2fs_lock_op(sbi);
+
for (i = 0; i < cc->cluster_size; i++) {
if (!cc->rpages[i])
continue;
@@ -1487,7 +1493,7 @@ static int f2fs_write_raw_pages(struct compress_ctx *cc,
if (!clear_page_dirty_for_io(cc->rpages[i]))
goto continue_unlock;

- ret = f2fs_write_single_data_page(cc->rpages[i], &_submitted,
+ ret = f2fs_write_single_data_page(cc->rpages[i], &submitted,
NULL, NULL, wbc, io_type,
compr_blocks, false);
if (ret) {
@@ -1495,26 +1501,29 @@ static int f2fs_write_raw_pages(struct compress_ctx *cc,
unlock_page(cc->rpages[i]);
ret = 0;
} else if (ret == -EAGAIN) {
+ ret = 0;
/*
* for quota file, just redirty left pages to
* avoid deadlock caused by cluster update race
* from foreground operation.
*/
if (IS_NOQUOTA(cc->inode))
- return 0;
- ret = 0;
+ goto out;
f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT);
goto retry_write;
}
- return ret;
+ goto out;
}

- *submitted += _submitted;
+ *submitted_p += submitted;
}

- f2fs_balance_fs(F2FS_M_SB(mapping), true);
+out:
+ if (compr_blocks > 0)
+ f2fs_unlock_op(sbi);

- return 0;
+ f2fs_balance_fs(sbi, true);
+ return ret;
}

int f2fs_write_multi_pages(struct compress_ctx *cc,
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index d00e92b6c9025..7a93a99fbd04b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2839,7 +2839,7 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
.encrypted_page = NULL,
.submitted = 0,
.compr_blocks = compr_blocks,
- .need_lock = LOCK_RETRY,
+ .need_lock = compr_blocks ? LOCK_DONE : LOCK_RETRY,
.post_read = f2fs_post_read_required(inode) ? 1 : 0,
.io_type = io_type,
.io_wbc = wbc,
@@ -2920,6 +2920,7 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
if (err == -EAGAIN) {
err = f2fs_do_write_data_page(&fio);
if (err == -EAGAIN) {
+ f2fs_bug_on(sbi, compr_blocks);
fio.need_lock = LOCK_REQ;
err = f2fs_do_write_data_page(&fio);
}
--
2.43.0