6.16-stable review patch. If anyone has any objections, please let me know.
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From: Yuezhang Mo Yuezhang.Mo@sony.com
[ Upstream commit c6993c4cb91803fceb82d6b5e0ec5e0aec2d0ad6 ]
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.Mo@sony.com Reviewed-by: Friendy Su friendy.su@sony.com Reviewed-by: Jacky Cao jacky.cao@sony.com Reviewed-by: Daniel Palmer daniel.palmer@sony.com Reviewed-by: Gao Xiang hsiangkao@linux.alibaba.com Reviewed-by: Hongbo Li lihongbo22@huawei.com Link: https://lore.kernel.org/r/20250804082030.3667257-2-Yuezhang.Mo@sony.com Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 799fef437aa8e..cad87e4d66943 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; @@ -330,7 +340,6 @@ 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)) @@ -661,14 +670,9 @@ 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;