From: Gao Xiang <hsiangkao@linux.alibaba.com> anolis inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB5UKT Reference: https://gitee.com/anolis/cloud-kernel/commit/52ffb0b7c3be -------------------------------- ANBZ: #1666 commit ba73eadd23d1c2dc5c8dc0c0ae2eeca2b9b709a7 upstream. When "-o device" mount option is not specified, scan the device table and instantiate the devices if there's any in the device table. In this case, the tag field of each device slot uniquely specifies a device. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20220512055601.106109-1-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Huang Jianan <jnhuang@linux.alibaba.com> Reviewed-by: Jeffle Xu <jefflexu@linux.alibaba.com> Signed-off-by: Baokun Li <libaokun1@huawei.com> --- fs/erofs/erofs_fs.h | 9 ++--- fs/erofs/super.c | 98 +++++++++++++++++++++++++++++++-------------- 2 files changed, 70 insertions(+), 37 deletions(-) diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h index b15a62bf2c46..9e2712976429 100644 --- a/fs/erofs/erofs_fs.h +++ b/fs/erofs/erofs_fs.h @@ -28,12 +28,9 @@ #define EROFS_SB_EXTSLOT_SIZE 16 struct erofs_deviceslot { - union { - u8 uuid[16]; /* used for device manager later */ - u8 userdata[64]; /* digest(sha256), etc. */ - } u; - __le32 blocks; /* total fs blocks of this device */ - __le32 mapped_blkaddr; /* map starting at mapped_blkaddr */ + u8 tag[64]; /* digest(sha256), etc. */ + __le32 blocks; /* total fs blocks of this device */ + __le32 mapped_blkaddr; /* map starting at mapped_blkaddr */ u8 reserved[56]; }; #define EROFS_DEVT_SLOT_SIZE sizeof(struct erofs_deviceslot) diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 5529c83d5d83..dabcab870a2a 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -123,7 +123,51 @@ static bool check_layout_compatibility(struct super_block *sb, return true; } -static int erofs_init_devices(struct super_block *sb, +static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, + struct erofs_device_info *dif, erofs_off_t *pos) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + struct erofs_deviceslot *dis; + struct block_device *bdev; + void *ptr; + int ret; + + ptr = erofs_read_metabuf(buf, sb, erofs_blknr(*pos), EROFS_KMAP); + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + dis = ptr + erofs_blkoff(*pos); + + if (!dif->path) { + if (!dis->tag[0]) { + erofs_err(sb, "empty device tag @ pos %llu", *pos); + return -EINVAL; + } + dif->path = kmemdup_nul(dis->tag, sizeof(dis->tag), GFP_KERNEL); + if (!dif->path) + return -ENOMEM; + } + + if (erofs_is_fscache_mode(sb)) { + ret = erofs_fscache_register_cookie(sb, &dif->fscache, + dif->path, false); + if (ret) + return ret; + } else { + bdev = blkdev_get_by_path(dif->path, FMODE_READ | FMODE_EXCL, + sb->s_type); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + dif->bdev = bdev; + } + + dif->blocks = le32_to_cpu(dis->blocks); + dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr); + sbi->total_blocks += dif->blocks; + *pos += EROFS_DEVT_SLOT_SIZE; + return 0; +} + +static int erofs_scan_devices(struct super_block *sb, struct erofs_super_block *dsb) { struct erofs_sb_info *sbi = EROFS_SB(sb); @@ -131,8 +175,6 @@ static int erofs_init_devices(struct super_block *sb, erofs_off_t pos; struct erofs_buf buf = __EROFS_BUF_INITIALIZER; struct erofs_device_info *dif; - struct erofs_deviceslot *dis; - void *ptr; int id, err = 0; sbi->total_blocks = sbi->primarydevice_blocks; @@ -141,7 +183,8 @@ static int erofs_init_devices(struct super_block *sb, else ondisk_extradevs = le16_to_cpu(dsb->extra_devices); - if (ondisk_extradevs != sbi->devs->extra_devices) { + if (sbi->devs->extra_devices && + ondisk_extradevs != sbi->devs->extra_devices) { erofs_err(sb, "extra devices don't match (ondisk %u, given %u)", ondisk_extradevs, sbi->devs->extra_devices); return -EINVAL; @@ -152,38 +195,31 @@ static int erofs_init_devices(struct super_block *sb, sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1; pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE; down_read(&sbi->devs->rwsem); - idr_for_each_entry(&sbi->devs->tree, dif, id) { - struct block_device *bdev; - - ptr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), - EROFS_KMAP); - if (IS_ERR(ptr)) { - err = PTR_ERR(ptr); - break; + if (sbi->devs->extra_devices) { + idr_for_each_entry(&sbi->devs->tree, dif, id) { + err = erofs_init_device(&buf, sb, dif, &pos); + if (err) + break; } - dis = ptr + erofs_blkoff(pos); + } else { + for (id = 0; id < ondisk_extradevs; id++) { + dif = kzalloc(sizeof(*dif), GFP_KERNEL); + if (!dif) { + err = -ENOMEM; + break; + } + err = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL); + if (err < 0) { + kfree(dif); + break; + } + ++sbi->devs->extra_devices; - if (erofs_is_fscache_mode(sb)) { - err = erofs_fscache_register_cookie(sb, &dif->fscache, - dif->path, false); + err = erofs_init_device(&buf, sb, dif, &pos); if (err) break; - } else { - bdev = blkdev_get_by_path(dif->path, - FMODE_READ | FMODE_EXCL, - sb->s_type); - if (IS_ERR(bdev)) { - err = PTR_ERR(bdev); - goto err_out; - } - dif->bdev = bdev; } - dif->blocks = le32_to_cpu(dis->blocks); - dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr); - sbi->total_blocks += dif->blocks; - pos += EROFS_DEVT_SLOT_SIZE; } -err_out: up_read(&sbi->devs->rwsem); erofs_put_metabuf(&buf); return err; @@ -255,7 +291,7 @@ static int erofs_read_superblock(struct super_block *sb) } /* handle multiple devices */ - ret = erofs_init_devices(sb, dsb); + ret = erofs_scan_devices(sb, dsb); out: erofs_put_metabuf(&buf); return ret; -- 2.46.1