[PATCH v3 2/2] staging: erofs: fix i_blocks calculation

From: Gao Xiang
Date: Mon May 27 2019 - 23:23:54 EST


For compressed files, i_blocks should not be calculated
by using i_size. use i_u.compressed_blocks instead.

In addition, i_blocks was miscalculated for non-compressed
files previously, fix it as well.

Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx>
---
change log v3:
- wrap i.u.compressed_blocks with le32_to_cpu() as Chao pointed out;

change log v2:
- fix description in commit message;
- fix to 'inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK'.

Thanks,
Gao Xiang

drivers/staging/erofs/inode.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index 1c220900e1a0..9520419f746c 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -20,6 +20,7 @@ static int read_inode(struct inode *inode, void *data)
struct erofs_vnode *vi = EROFS_V(inode);
struct erofs_inode_v1 *v1 = data;
const unsigned int advise = le16_to_cpu(v1->i_advise);
+ erofs_blk_t nblks = 0;

vi->data_mapping_mode = __inode_data_mapping(advise);

@@ -60,6 +61,10 @@ static int read_inode(struct inode *inode, void *data)
le32_to_cpu(v2->i_ctime_nsec);

inode->i_size = le64_to_cpu(v2->i_size);
+
+ /* total blocks for compressed files */
+ if (vi->data_mapping_mode == EROFS_INODE_LAYOUT_COMPRESSION)
+ nblks = le32_to_cpu(v2->i_u.compressed_blocks);
} else if (__inode_version(advise) == EROFS_INODE_LAYOUT_V1) {
struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);

@@ -90,6 +95,8 @@ static int read_inode(struct inode *inode, void *data)
sbi->build_time_nsec;

inode->i_size = le32_to_cpu(v1->i_size);
+ if (vi->data_mapping_mode == EROFS_INODE_LAYOUT_COMPRESSION)
+ nblks = le32_to_cpu(v1->i_u.compressed_blocks);
} else {
errln("unsupported on-disk inode version %u of nid %llu",
__inode_version(advise), vi->nid);
@@ -97,8 +104,11 @@ static int read_inode(struct inode *inode, void *data)
return -EIO;
}

- /* measure inode.i_blocks as the generic filesystem */
- inode->i_blocks = ((inode->i_size - 1) >> 9) + 1;
+ if (!nblks)
+ /* measure inode.i_blocks as generic filesystems */
+ inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
+ else
+ inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
return 0;
}

--
2.17.1