On 2025/8/4 16:20, Yuezhang Mo wrote:
If using multiple devices, we should check if the extra device support DAX instead of checking the primary device when deciding if to use DAX to access a file. If an extra device does not support DAX we should fallback to normal access otherwise the data on that device will be inaccessible. Signed-off-by: Yuezhang Mo <yuezhang...@sony.com> Reviewed-by: Friendy Su <friendy...@sony.com> Reviewed-by: Jacky Cao <jacky....@sony.com> Reviewed-by: Daniel Palmer <daniel.pal...@sony.com>
Reviewed-by: Hongbo Li <lihongb...@huawei.com> Thanks, Hongbo
--- Changes of v3: - uniformly use erofs_info() to output the logs of turning off DAX Changes of v2: - fix the indentation alignment of `dif->path` - remove the unnecessary comment fs/erofs/super.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/fs/erofs/super.c b/fs/erofs/super.c index e1020aa60771..8c7a5985b4ee 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -174,6 +174,11 @@ 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; @@ -210,8 +215,13 @@ static int erofs_scan_devices(struct super_block *sb, ondisk_extradevs, sbi->devs->extra_devices); return -EINVAL; } - if (!ondisk_extradevs) + 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 (!sbi->devs->extra_devices && !erofs_is_fscache_mode(sb))sbi->devs->flatdev = true; @@ -338,7 +348,6 @@ static int erofs_read_superblock(struct super_block *sb) if (ret < 0) goto out;- /* handle multiple devices */ret = erofs_scan_devices(sb, dsb);if (erofs_sb_has_48bit(sbi))@@ -671,14 +680,9 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) return invalfc(fc, "cannot use fsoffset in fscache mode"); }- if (test_opt(&sbi->opt, DAX_ALWAYS)) {- if (!sbi->dif0.dax_dev) { - errorfc(fc, "DAX unsupported by block device. Turning off DAX."); - clear_opt(&sbi->opt, DAX_ALWAYS); - } else if (sbi->blkszbits != PAGE_SHIFT) { - errorfc(fc, "unsupported blocksize for DAX"); - clear_opt(&sbi->opt, DAX_ALWAYS); - } + if (test_opt(&sbi->opt, DAX_ALWAYS) && sbi->blkszbits != PAGE_SHIFT) { + erofs_info(sb, "unsupported blocksize for DAX"); + clear_opt(&sbi->opt, DAX_ALWAYS); }sb->s_time_gran = 1;
