On 2024/3/25 10:14, Shinichiro Kawasaki wrote:
On Mar 24, 2024 / 20:13, Chao Yu wrote:
Hi Shinichiro,

Can you please check below diff? IIUC, for the case: f2fs_map_blocks()
returns zero blkaddr in non-primary device, which is a verified valid
block address, we'd better to check m_flags & F2FS_MAP_MAPPED instead
of map.m_pblk != NULL_ADDR to decide whether tagging IOMAP_MAPPED flag
or not.

  fs/f2fs/data.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 6f66e3e4221a..41a56d4298c8 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -4203,7 +4203,7 @@ static int f2fs_iomap_begin(struct inode *inode, loff_t 
offset, loff_t length,
        if (WARN_ON_ONCE(map.m_pblk == COMPRESS_ADDR))
                return -EINVAL;

-       if (map.m_pblk != NULL_ADDR) {
+       if (map.m_flags & F2FS_MAP_MAPPED) {
                iomap->length = blks_to_bytes(inode, map.m_len);
                iomap->type = IOMAP_MAPPED;
                iomap->flags |= IOMAP_F_MERGED;

Thanks Chao, I confirmed that the diff above avoids the WARN and zbd/010
failure. From that point of view, it looks good.

Thank you for the confirmation. :)

One thing I noticed is that the commit message of 8d3c1fa3fa5ea ("f2fs:
don't rely on F2FS_MAP_* in f2fs_iomap_begin") says that f2fs_map_blocks()
might be setting F2FS_MAP_* flag on a hole, and that's why the commit
avoided the F2FS_MAP_MAPPED flag check. So I was not sure if it is the
right thing to reintroduce the flag check.

I didn't see such logic in previous f2fs_map_blocks(, F2FS_GET_BLOCK_DIO) 
I doubt it hits the same case: map.m_pblk is valid zero blkaddr which locates in
the head of secondary device? What do you think?

Quoted commit message from 8d3c1fa3fa5ea:

When testing with a mixed zoned / convention device combination, there
are regular but not 100% reproducible failures in xfstests generic/113
where the __is_valid_data_blkaddr assert hits due to finding a hole.

Previous code:

-       if (map.m_flags & (F2FS_MAP_MAPPED | F2FS_MAP_UNWRITTEN)) {
-               iomap->length = blks_to_bytes(inode, map.m_len);
-               if (map.m_flags & F2FS_MAP_MAPPED) {
-                       iomap->type = IOMAP_MAPPED;
-                       iomap->flags |= IOMAP_F_MERGED;
-               } else {
-                       iomap->type = IOMAP_UNWRITTEN;
-               }
-               if (WARN_ON_ONCE(!__is_valid_data_blkaddr(map.m_pblk)))
-                       return -EINVAL;


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