Messages in this thread | | | Date | Wed, 1 Mar 2023 15:08:48 +0800 | Subject | Re: [PATCH] erofs: support for mounting a single block device with multiple devices | From | Gao Xiang <> |
| |
Hi Jia,
On 2023/3/1 15:04, Jia Zhu wrote: > In order to support mounting multi-layer container image as a block > device, add single block device with multiple devices feature for EROFS.
In order to support mounting multi-blob container image as a single flattened block device, add flattened block device feature for EROFS.
> > In this mode, all meta/data contents will be mapped into one block address. > User could directly mount the block device by EROFS. > > Signed-off-by: Jia Zhu <zhujia.zj@bytedance.com> > Reviewed-by: Xin Yin <yinxin.x@bytedance.com> > --- > fs/erofs/data.c | 8 ++++++-- > fs/erofs/super.c | 5 +++++ > 2 files changed, 11 insertions(+), 2 deletions(-) > > diff --git a/fs/erofs/data.c b/fs/erofs/data.c > index e16545849ea7..870b1f7fe1d4 100644 > --- a/fs/erofs/data.c > +++ b/fs/erofs/data.c > @@ -195,9 +195,9 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) > { > struct erofs_dev_context *devs = EROFS_SB(sb)->devs; > struct erofs_device_info *dif; > + bool flatdev = !!sb->s_bdev;
I'd like to land it in sbi and set it in advance?
Also, did you test this patch?
Thanks, Gao Xiang
> int id; > > - /* primary device by default */ > map->m_bdev = sb->s_bdev; > map->m_daxdev = EROFS_SB(sb)->dax_dev; > map->m_dax_part_off = EROFS_SB(sb)->dax_part_off; > @@ -210,12 +210,16 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map) > up_read(&devs->rwsem); > return -ENODEV; > } > + if (flatdev) { > + map->m_pa += blknr_to_addr(dif->mapped_blkaddr); > + map->m_deviceid = 0; > + } > map->m_bdev = dif->bdev; > map->m_daxdev = dif->dax_dev; > map->m_dax_part_off = dif->dax_part_off; > map->m_fscache = dif->fscache; > up_read(&devs->rwsem); > - } else if (devs->extra_devices) { > + } else if (devs->extra_devices && !flatdev) { > down_read(&devs->rwsem); > idr_for_each_entry(&devs->tree, dif, id) { > erofs_off_t startoff, length; > diff --git a/fs/erofs/super.c b/fs/erofs/super.c > index 19b1ae79cec4..4f9725b0950c 100644 > --- a/fs/erofs/super.c > +++ b/fs/erofs/super.c > @@ -226,6 +226,7 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, > struct erofs_fscache *fscache; > struct erofs_deviceslot *dis; > struct block_device *bdev; > + bool flatdev = !!sb->s_bdev; > void *ptr; > > ptr = erofs_read_metabuf(buf, sb, erofs_blknr(*pos), EROFS_KMAP); > @@ -248,6 +249,10 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, > if (IS_ERR(fscache)) > return PTR_ERR(fscache); > dif->fscache = fscache; > + } else if (flatdev) { > + dif->bdev = sb->s_bdev; > + dif->dax_dev = EROFS_SB(sb)->dax_dev; > + dif->dax_part_off = sbi->dax_part_off; > } else { > bdev = blkdev_get_by_path(dif->path, FMODE_READ | FMODE_EXCL, > sb->s_type);
| |