From ebe96a42f940231e07640d43cb87f81f3f706d82 Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Sun, 1 Nov 2020 03:51:02 +0800 Subject: [PATCH] erofs: derive atime instead of leaving it empty 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 # 4.19+ Reported-by: nl6720 Reviewed-by: Chao Yu [ Gao Xiang: Manually backport to 4.19.y due to trivial conflicts. ] Signed-off-by: Gao Xiang Signed-off-by: Greg Kroah-Hartman --- drivers/staging/erofs/inode.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c index 7448744cc5159..12a5be95457f8 100644 --- a/drivers/staging/erofs/inode.c +++ b/drivers/staging/erofs/inode.c @@ -53,11 +53,9 @@ static int read_inode(struct inode *inode, void *data) 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 *inode, void *data) 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 *inode, void *data) 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; -- 2.47.3