From: Zhan Xusheng Date: Fri, 3 Apr 2026 06:36:58 +0000 (+0800) Subject: erofs: handle 48-bit blocks/uniaddr for extra devices X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=63c2f06198ca7513433f1c92f2c654869d72417e;p=thirdparty%2Fkernel%2Flinux.git erofs: handle 48-bit blocks/uniaddr for extra devices erofs_init_device() only reads blocks_lo and uniaddr_lo from the on-disk device slot, ignoring blocks_hi and uniaddr_hi that were introduced alongside the 48-bit block addressing feature. For the primary device (dif0), erofs_read_superblock() already handles this correctly by combining blocks_lo with blocks_hi when 48-bit layout is enabled. But the same logic was not applied to extra devices. With a 48-bit EROFS image using extra devices whose uniaddr or blocks exceed 32-bit range, the truncated values cause erofs_map_dev() to compute wrong physical addresses, leading to silent data corruption. Fix this by reading blocks_hi and uniaddr_hi in erofs_init_device() when 48-bit layout is enabled, consistent with the primary device handling. Also fix the erofs_deviceslot on-disk definition where blocks_hi was incorrectly declared as __le32 instead of __le16. Fixes: 61ba89b57905 ("erofs: add 48-bit block addressing on-disk support") Suggested-by: Gao Xiang Signed-off-by: Zhan Xusheng Reviewed-by: Gao Xiang Signed-off-by: Gao Xiang --- diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h index b80c6bb33a58c..7871b16c1d333 100644 --- a/fs/erofs/erofs_fs.h +++ b/fs/erofs/erofs_fs.h @@ -44,9 +44,9 @@ struct erofs_deviceslot { u8 tag[64]; /* digest(sha256), etc. */ __le32 blocks_lo; /* total blocks count of this device */ __le32 uniaddr_lo; /* unified starting block of this device */ - __le32 blocks_hi; /* total blocks count MSB */ + __le16 blocks_hi; /* total blocks count MSB */ __le16 uniaddr_hi; /* unified starting block MSB */ - u8 reserved[50]; + u8 reserved[52]; }; #define EROFS_DEVT_SLOT_SIZE sizeof(struct erofs_deviceslot) diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 972a0c82198d7..802add6652fda 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -129,6 +129,7 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, struct erofs_fscache *fscache; struct erofs_deviceslot *dis; struct file *file; + bool _48bit; dis = erofs_read_metabuf(buf, sb, *pos, false); if (IS_ERR(dis)) @@ -175,8 +176,11 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb, dif->file = file; } - dif->blocks = le32_to_cpu(dis->blocks_lo); - dif->uniaddr = le32_to_cpu(dis->uniaddr_lo); + _48bit = erofs_sb_has_48bit(sbi); + dif->blocks = le32_to_cpu(dis->blocks_lo) | + (_48bit ? (u64)le16_to_cpu(dis->blocks_hi) << 32 : 0); + dif->uniaddr = le32_to_cpu(dis->uniaddr_lo) | + (_48bit ? (u64)le16_to_cpu(dis->uniaddr_hi) << 32 : 0); sbi->total_blocks += dif->blocks; *pos += EROFS_DEVT_SLOT_SIZE; return 0;