From: Gao Xiang hsiangkao@redhat.com
commit d3938ee23e97bfcac2e0eb6b356875da73d700df upstream.
EROFS has _only one_ ondisk timestamp (ctime is currently documented and recorded, we might also record mtime instead with a new compat feature if needed) for each extended inode since EROFS isn't mainly for archival purposes so no need to keep all timestamps on disk especially for Android scenarios due to security concerns. Also, romfs/cramfs don't have their own on-disk timestamp, and squashfs only records mtime instead.
Let's also derive access time from ondisk timestamp rather than leaving it empty, and if mtime/atime for each file are really needed for specific scenarios as well, we can also use xattrs to record them then.
Link: https://lore.kernel.org/r/20201031195102.21221-1-hsiangkao@aol.com [ Gao Xiang: It'd be better to backport for user-friendly concern. ] Fixes: 431339ba9042 ("staging: erofs: add inode operations") Cc: stable stable@vger.kernel.org # 4.19+ Reported-by: nl6720 nl6720@gmail.com Reviewed-by: Chao Yu yuchao0@huawei.com [ Gao Xiang: Manually backport to 4.19.y due to trivial conflicts. ] Signed-off-by: Gao Xiang hsiangkao@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/erofs/inode.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)
--- a/drivers/staging/erofs/inode.c +++ b/drivers/staging/erofs/inode.c @@ -53,11 +53,9 @@ static int read_inode(struct inode *inod i_gid_write(inode, le32_to_cpu(v2->i_gid)); set_nlink(inode, le32_to_cpu(v2->i_nlink));
- /* ns timestamp */ - inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = - le64_to_cpu(v2->i_ctime); - inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = - le32_to_cpu(v2->i_ctime_nsec); + /* extended inode has its own timestamp */ + inode->i_ctime.tv_sec = le64_to_cpu(v2->i_ctime); + inode->i_ctime.tv_nsec = le32_to_cpu(v2->i_ctime_nsec);
inode->i_size = le64_to_cpu(v2->i_size); } else if (__inode_version(advise) == EROFS_INODE_LAYOUT_V1) { @@ -83,11 +81,9 @@ static int read_inode(struct inode *inod i_gid_write(inode, le16_to_cpu(v1->i_gid)); set_nlink(inode, le16_to_cpu(v1->i_nlink));
- /* use build time to derive all file time */ - inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = - sbi->build_time; - inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = - sbi->build_time_nsec; + /* use build time for compact inodes */ + inode->i_ctime.tv_sec = sbi->build_time; + inode->i_ctime.tv_nsec = sbi->build_time_nsec;
inode->i_size = le32_to_cpu(v1->i_size); } else { @@ -97,6 +93,11 @@ static int read_inode(struct inode *inod return -EIO; }
+ inode->i_mtime.tv_sec = inode->i_ctime.tv_sec; + inode->i_atime.tv_sec = inode->i_ctime.tv_sec; + inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec; + inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec; + /* measure inode.i_blocks as the generic filesystem */ inode->i_blocks = ((inode->i_size - 1) >> 9) + 1; return 0;