6.18-stable review patch. If anyone has any objections, please let me know.

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From: Gao Xiang hsiangkao@linux.alibaba.com

[ Upstream commit ebe4f3f6eb0c10f87c58e52a8912694c14fdeda6 ]

The detection of the primary device is skipped incorrectly if the multiple or flattened feature is enabled.

It also fixes the FSDAX misdetection for non-block extra blobs.

Fixes: c6993c4cb918 ("erofs: Fallback to normal access if DAX is not supported on extra device") Reported-and-tested-by: syzbot+31b8fb02cb8a25bd5e78@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/691af9f6.a70a0220.3124cb.0097.GAE@google.com Cc: Yuezhang Mo Yuezhang.Mo@sony.com Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/erofs/super.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/fs/erofs/super.c b/fs/erofs/super.c index f3f8d8c066e4e..cd8ff98c29384 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -174,15 +174,15 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, if (!erofs_is_fileio_mode(sbi)) { dif->dax_dev = fs_dax_get_by_bdev(file_bdev(file), &dif->dax_part_off, NULL, NULL); - if (!dif->dax_dev && test_opt(&sbi->opt, DAX_ALWAYS)) { - erofs_info(sb, "DAX unsupported by %s. Turning off DAX.", - dif->path); - clear_opt(&sbi->opt, DAX_ALWAYS); - } } else if (!S_ISREG(file_inode(file)->i_mode)) { fput(file); return -EINVAL; } + if (!dif->dax_dev && test_opt(&sbi->opt, DAX_ALWAYS)) { + erofs_info(sb, "DAX unsupported by %s. Turning off DAX.", + dif->path); + clear_opt(&sbi->opt, DAX_ALWAYS); + } dif->file = file; }

@@ -215,13 +215,13 @@ static int erofs_scan_devices(struct super_block *sb, ondisk_extradevs, sbi->devs->extra_devices); return -EINVAL; } - if (!ondisk_extradevs) { - if (test_opt(&sbi->opt, DAX_ALWAYS) && !sbi->dif0.dax_dev) { - erofs_info(sb, "DAX unsupported by block device. Turning off DAX."); - clear_opt(&sbi->opt, DAX_ALWAYS); - } - return 0; + + if (test_opt(&sbi->opt, DAX_ALWAYS) && !sbi->dif0.dax_dev) { + erofs_info(sb, "DAX unsupported by block device. Turning off DAX."); + clear_opt(&sbi->opt, DAX_ALWAYS); } + if (!ondisk_extradevs) + return 0;

if (!sbi->devs->extra_devices && !erofs_is_fscache_mode(sb)) sbi->devs->flatdev = true;