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")
Signed-off-by: Chao Yu <c...@kernel.org>
---
 fs/f2fs/compress.c | 20 ++++++++++++++------
 fs/f2fs/data.c     |  3 ++-
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 1122db8cc0b0..a1426c3eadcc 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1471,7 +1471,8 @@ static int f2fs_write_raw_pages(struct compress_ctx *cc,
                                        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, ret = 0, i;
 
        compr_blocks = f2fs_compressed_blocks(cc);
 
@@ -1486,6 +1487,10 @@ 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;
@@ -1518,26 +1523,29 @@ 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;
        }
 
-       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 6c72a6e86ba8..ceed5ac6c66b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2848,7 +2848,7 @@ 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,
@@ -2929,6 +2929,7 @@ 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);
                }
-- 
2.40.1



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